Raise an error if a user tries to register with an excessively long username

Summary: Fixes T2348. We should probably do some of this more broadly, but can tackle them one at a time as they arise, since many fields have no effective length limit.

Test Plan: {F54126}

Reviewers: btrahan, asherkin

Reviewed By: asherkin

CC: aran

Maniphest Tasks: T2348

Differential Revision: https://secure.phabricator.com/D6744
Allow only one global top menu to be open at a time

Summary: Fixes T3715. Makes "visible" global instead of per-menu, so all the menus share a visible state.

Test Plan: For menus A and B, clicked "A, A", "A, B, A", "A, B, B", "A, B, B, A", etc. Couldn't figure out a way to break it.

Reviewers: btrahan, chad

Reviewed By: chad

CC: aran

Maniphest Tasks: T3715

Differential Revision: https://secure.phabricator.com/D6745
Differential - add an undo element when you collapse a file

Summary: Fixes T2258.

Test Plan: collapsed and expanded file via the dropdown - good stuff. got the "undo" element into the mix - also good stuff.

Reviewers: epriestley

Reviewed By: epriestley

CC: chad, Korvin, aran

Maniphest Tasks: T2258

Differential Revision: https://secure.phabricator.com/D6742
Better JS for Differential File Collapsing Undo

Summary: take epriestley's feedback 'cuz its good

Test Plan: collapse, expand, use undo like a rockstar. observe proper behavior

Reviewers: epriestley

Reviewed By: epriestley

CC: Korvin, aran

Maniphest Tasks: T2258

Differential Revision: https://secure.phabricator.com/D6748
Make Flags policy aware

Summary:
Ref T1809. Ref T603. Ref T3599. Makes flags policy aware.

This change reduces the utility of flag search/browse; the next change will switch it to ApplicationSearch to restore utility. Representing all that ordering in terms of cursor paging is also a giant pain.

Test Plan: Viewed Differential, Flags, etc. Grepped for all PhabricatorFlagQuery callsites.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T603, T1809, T3599

Differential Revision: https://secure.phabricator.com/D6746
Implement ApplicationSearch in Flags

Summary:
Ref T1809. Provide ApplicationSearch to Flags and allow the user to select flags by color.

@chad might have some design feedback on my control.

Test Plan: {F54131}

Reviewers: btrahan, chad

Reviewed By: chad

CC: aran

Maniphest Tasks: T1809

Differential Revision: https://secure.phabricator.com/D6747
Remove all reads of `ReleephProject->repositoryID`

Summary:
Ref T3655. ReleephProject currently has both `repositoryID` and `repositoryPHID`, which point to the same object and are reudundant. Get rid of all reads of `repositoryID`.

NOTE: This makes project loads depend on repository loads. The eventual rule here will be that you must be able to see a repository in order to see projects for that repository, which seems like a reasonable rule. We might need to tailor it more than this (e.g., if there are branch read permissions down the line) but this seems like a reasonable minimum.

Test Plan: Grepped for `repositoryID` in `releeph/`. Called `releeph.getbranches`.

Reviewers: btrahan

Reviewed By: btrahan

CC: LegNeato, aran

Maniphest Tasks: T3655

Differential Revision: https://secure.phabricator.com/D6633
Remove ReleephProject->repositoryID writes

Summary: Ref T3655. Depends on D6633. This removes the writes and the column.

Test Plan: Created a project, edited a project. Verified the table doesn't have any keys including this column.

Reviewers: btrahan

Reviewed By: btrahan

CC: LegNeato, aran

Maniphest Tasks: T3655

Differential Revision: https://secure.phabricator.com/D6634
Remove "Project ID" from Releeph Projects

Summary:
Fixes T3660. Releeph Projects currently have an unused one-to-one mapping to Phabricator projects. This isn't consistent with other applications and has no integrations or uses. Get rid of it.

NOTE: Waiting for signoff from @legneato on T3660 before pulling the trigger here.

Test Plan: Created and edited Releeph projects. Grepped for references to project ID; there are a dozen or so but they're all either Releeph projects or Arcanist projects.

Reviewers: btrahan

Reviewed By: btrahan

CC: LegNeato, aran

Maniphest Tasks: T3660

Differential Revision: https://secure.phabricator.com/D6635
Remove "cut point commit identifier" from Releeph

Summary: Ref T3656. Releeph denormalizes branch cut point identifiers into Branch objects, but this information isn't useful or used for sorting, filtering, or enforcing unique constraints. Instead, derive it via noramlized pathways from the `cutPointCommitPHID`.

Test Plan: Ran storage upgrade. Ran `releephwork.getbranch` and `releeph.getbranches`. Grepped for `cutPointCommitIdentifier`.

Reviewers: btrahan

Reviewed By: btrahan

CC: LegNeato, aran

Maniphest Tasks: T3656

Differential Revision: https://secure.phabricator.com/D6636
Support configuration-driven custom fields

Summary:
Ref T1702. Ref T3718. There are a couple of things going on here:

**PhabricatorCustomFieldList**: I added `PhabricatorCustomFieldList`, which is just a convenience class for dealing with lists of fields. Often, current field code does something like this inline in a Controller:

  foreach ($fields as $field) {
    // do some junk
  }

Often, that junk has some slightly subtle implications. Move all of it to `$list->doSomeJunk()` methods (like `appendFieldsToForm()`, `loadFieldsFromStorage()`) to reduce code duplication and prevent errors. This additionally moves an existing list-convenience method there, out of `PhabricatorPropertyListView`.

**PhabricatorUserConfiguredCustomFieldStorage**: Adds `PhabricatorUserConfiguredCustomFieldStorage` for storing custom field data (like "ICQ Handle", "Phone Number", "Desk", "Favorite Flower", etc).

**Configuration-Driven Custom Fields**: Previously, I was thinking about doing these with interfaces, but as I thought about it more I started to dislike that approach. Instead, I built proxies into `PhabricatorCustomField`. Basically, this means that fields (like a custom, configuration-driven "Favorite Flower" field) can just use some other Field to actually provide their implementation (like a "standard" field which knows how to render text areas). The previous approach would have involed subclasssing the "standard" field and implementing an interface, but that would mean that every application would have at least two "base" fields and generally just seemed bleh as I worked through it.

The cost of this approach is that we need a bunch of `proxy` junk in the base class, but that's a one-time cost and I think it simplifies all the implementations and makes them a lot less magical (e.g., all of the custom fields now extend the right base field classes).

**Fixed Some Bugs**: Some of this code hadn't really been run yet and had minor bugs.

Test Plan:
{F54240}
{F54241}
{F54242}

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T1702, T1703, T3718

Differential Revision: https://secure.phabricator.com/D6749
Partially move Releeph custom fields to PhabricatorCustomField

Summary:
Fixes T3661. Ref T3718. This makes Releeph custom fields extend PhabricatorCustomField so we can start moving over other pieces of infrastructure (rendering, storage, etc) to run through the same pathways. It's roughly the minimum amount of work required to be able to move forward.

NOTE: This removes per-project custom field selectors. Fields are now configured for an entire install. My understanding is that Facebook does not use this feature, and modern field infrastructure has moved away from selectors.

Test Plan: Viewed and edited projects, branches, and requests in Releeph. Grepped for removed config. Grepped for `field_selector`.

Reviewers: btrahan

Reviewed By: btrahan

CC: LegNeato, aran

Maniphest Tasks: T3661, T3718

Differential Revision: https://secure.phabricator.com/D6750
Simplify and improve PhabricatorCustomField APIs

Summary:
Ref T1703. Ref T3718. The `PhabricatorCustomFieldList` seems like a pretty good idea. Move more code into it to make it harder to get wrong.

Also the sequencing on old/new values for these transactions was a bit off; fix that up.

Test Plan: Edited standard and custom profile fields.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T1703, T3718

Differential Revision: https://secure.phabricator.com/D6751
Further simplify PhabricatorCustomFieldInterface

Summary:
Ref T1703. Ref T3718. This introduces `PhabricatorCustomFieldAttachment`, which is just a fancy `array()`. The goal here is to simplify `PhabricatorCustomFieldInterface` as much as possible.

In particular, it can now use common infrastructure (`assertAttached()`) and is more difficult to get wrong.

Test Plan: Edited custom fields on profile.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T1703, T3718

Differential Revision: https://secure.phabricator.com/D6752
Make ReleephRequest implement PhabricatorCustomFieldInterface

Summary: Ref T3718. Doesn't do anything yet.

Test Plan: Viewed and edited a request.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T3718

Differential Revision: https://secure.phabricator.com/D6753
Partially fix a policy issue with ApplicationTransactions

Summary: Currently, we check that the user can view and edit their own transaction, which is always true. Instead, check that they can view the object. I'll fix this with a more tailored check against the EDIT capability that's per-transaction later.

Test Plan: Applying no transactions no longer fatals with undefined `$xaction`.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Differential Revision: https://secure.phabricator.com/D6754
Delete "Risk" field specification from Releeph

Summary: Ref T3718. This is not used and does not seem particularly useful.

Test Plan: Grep.

Reviewers: btrahan

Reviewed By: btrahan

CC: LegNeato, aran

Maniphest Tasks: T3718

Differential Revision: https://secure.phabricator.com/D6755
Add hovercard on/off option to PhabricatorFeedStory

Summary: Defaults hovercards off everywhere feed stories are shown. I tried to find where to put this in so /feed/ could display them, but got horribly lost and confused in SearchQueryLandView

Test Plan: turn hovercards on and off, inspect elements.

Reviewers: epriestley, btrahan

Reviewed By: epriestley

CC: Korvin, aran

Differential Revision: https://secure.phabricator.com/D6757
Use PhabricatorCustomField infrastructure to render Releeph custom fields on the edit screen

Summary:
Ref T3718. This moves custom field rendering on the edit screen to PhabricatorCustomField and makes all the APIs conformant.

We still run through edit with both old-school and new-school sets of fields, because the actual editing isn't on the new stuff yet. That will happen in a diff or two.

Test Plan: Edited a request; intentionally introduced errors and verified the form behaved as expected.

Reviewers: btrahan, testuser1122344

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T3718

Differential Revision: https://secure.phabricator.com/D6756
Add `src/extensions/` to Phabricator

Summary: I added this easier-extension mechanism a while ago but only added the actual directories to libphutil and arcanist. This one should work, it just wasn't checked into the repository.

Test Plan: Added a file with an exception in it to the directory, verified the exception was thrown at runtime.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Differential Revision: https://secure.phabricator.com/D6759