Require high-security session to sign legal documents

Summary: Ref T3116. If you have MFA on your account, require a code to sign a legal document.

Test Plan: Signed legal documents, got checkpointed.

Reviewers: btrahan, chad

Reviewed By: chad

Subscribers: epriestley

Maniphest Tasks: T3116

Differential Revision: https://secure.phabricator.com/D9772
Allow Legalpad documents to be destroyed with `bin/remove destroy`

Summary: Ref T3116. Support permanent destruction of legal document objects.

Test Plan: Ran `bin/remove destroy L1`, saw it clean up the document body, signatures, transactions and edges.

Reviewers: btrahan, chad

Reviewed By: chad

Subscribers: epriestley

Maniphest Tasks: T3116

Differential Revision: https://secure.phabricator.com/D9775
Allow users to search for signatures by name and email substrings

Summary:
Ref T3116. In the case of anonymous signers, there's no way to do a quick way to check if someone has signed a doc since you can't query by their (nonexistent) external account ID.

Move "name" and "email" to first-class columns and let the engine search for them.

Test Plan: Searched for signatures with name and email fragments.

Reviewers: btrahan, chad

Reviewed By: chad

Subscribers: epriestley

Maniphest Tasks: T3116

Differential Revision: https://secure.phabricator.com/D9776
Allow Herald to "Require legal signatures" for reviews

Summary:
Ref T3116. Add a Herald action "Require legal signatures" which requires revision authors to accept legal agreements before their revisions can be accepted.

  - Herald will check which documents the author has signed, and trigger a "you have to sign X, Y, Z" for other documents.
  - If the author has already signed everything, we don't spam the revision -- basically, this only triggers when signatures are missing.
  - The UI will show which documents must be signed and warn that the revision can't be accepted until they're completed.
  - Users aren't allowed to "Accept" the revision until documents are cleared.

Fixes T1157. The original install making the request (Hive) no longer uses Phabricator, and this satisfies our requirements.

Test Plan:
  - Added a Herald rule.
  - Created a revision, saw the rule trigger.
  - Viewed as author and non-author, saw field UI (generic for non-author, specific for author), transaction UI, and accept-warning UI.
  - Tried to accept revision.
  - Signed document, saw UI update. Note that signatures don't currently //push// an update to the revision, but could eventually (like blocking tasks work).
  - Accepted revision.
  - Created another revision, saw rules not add the document (since it's already signed, this is the "no spam" case).

Reviewers: btrahan, chad

Reviewed By: chad

Subscribers: asherkin, epriestley

Maniphest Tasks: T1157, T3116

Differential Revision: https://secure.phabricator.com/D9771
Add some basic documentation for Legalpad

Summary: Ref T3116. Explain a couple of core use cases and contextualize the app a bit.

Test Plan: Read application help screen and user guide.

Reviewers: btrahan, chad

Reviewed By: chad

Subscribers: epriestley

Maniphest Tasks: T3116

Differential Revision: https://secure.phabricator.com/D9777
Only show text encoding note in Differential if a change has hunks

Summary: Fixes T5503. We incorrectly render an encoding note for empty files. Only render an encoding note for text changes with at least one hunk.

Test Plan:
  - Viewed empty file, no note.
  - Viewed nonempty file with altered encoding, saw note.

Reviewers: btrahan, joshuaspence

Reviewed By: joshuaspence

Subscribers: epriestley

Maniphest Tasks: T5503

Differential Revision: https://secure.phabricator.com/D9780
Add a "Can Create Documents" permission for Legalpad

Summary: Ref T3116. Installs might reasonably want to restrict creation of these documents to actual lawyers or something.

Test Plan: Adjusted policy, tried to create document, set it back, created a document.

Reviewers: btrahan, chad

Reviewed By: chad

Subscribers: epriestley

Maniphest Tasks: T3116

Differential Revision: https://secure.phabricator.com/D9778
Unbeta Legalpad

Summary: Fixes T3116. This app is still pretty basic, but solves a real problem and doesn't have any major missing features.

Test Plan: Observed no "Beta" on launcher.

Reviewers: btrahan, chad

Reviewed By: chad

Subscribers: epriestley

Maniphest Tasks: T3116

Differential Revision: https://secure.phabricator.com/D9774
Merge branch 'master' into cyyun
Various minor JSHint fixes.

Summary: Various fixes as suggested by JSHint.

Test Plan: Eye-balled it.

Reviewers: #blessed_reviewers, epriestley

Reviewed By: #blessed_reviewers, epriestley

Subscribers: epriestley, Korvin

Differential Revision: https://secure.phabricator.com/D9783
Merge branch 'master' into cyyun
Don't atomize closures

Summary: In a PHP5.3+ codebase with closures, Diviner would pick up anonymous functions and add them into the generated documentation. This causes them to be skipped.

Test Plan: Ran `bin/diviner generate --clean` before and after change, no longer got a bunch of unnamed functions dumped into the documentation.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: epriestley, Korvin

Differential Revision: https://secure.phabricator.com/D9786
Add flat text assertions to Phabricator remarkup rules

Summary: Remarkup rules can not safely use arbitrary text in tag attributes,
because it may include tokens which are later replaced. Precedence rules
should prevent this in general. Use flat text assertions and adjust precedence
rules in cases where they may not prevent tokens from appearing in attributes.

Auditors: btrahan
Adjust remarkup rule precedence for embeds

Summary: The monospaced rule should still have higher precedence than these
rules, so use flat text tests to cover some rule interactions.

Auditors: btrahan
Bump remarkup version for new precedence/flat text rules

Summary: Clear any existing caches with old precedence rules.

Auditors: btrahan
Fix bad method call name.
Allow dashboard panels to be archived

Summary: Ref T5471. Adds an archived state for panels. Archived panels don't show up in the default query view or in the "Add Existing Panel" workflow.

Test Plan:
  - Archived a panel.
  - Activated a panel.
  - Viewed / searched for archived/active panels.
  - Popped "Add Existing Panel" dropdown and saw it omit archived panels.

Reviewers: chad

Reviewed By: chad

Subscribers: epriestley

Maniphest Tasks: T5471

Differential Revision: https://secure.phabricator.com/D9779
Support custom actions in Herald

Summary:
This was significantly easier than expected.  Here's an example of what an extension class might look like:

```
<?php

final class AddRiskReviewHeraldCustomAction extends HeraldCustomAction {

  public function appliesToAdapter(HeraldAdapter $adapter) {
    return $adapter instanceof HeraldDifferentialRevisionAdapter;
  }

  public function appliesToRuleType($rule_type) {
    return $rule_type == HeraldRuleTypeConfig::RULE_TYPE_GLOBAL ||
      $rule_type == HeraldRuleTypeConfig::RULE_TYPE_OBJECT;
  }

  public function getActionKey() {
    return 'custom:add-risk';
  }

  public function getActionName() {
    return 'Add risk rating (JSON)';
  }

  public function getActionType() {
    return HeraldAdapter::VALUE_TEXT;
  }

  public function applyEffect(
    HeraldAdapter $adapter,
    $object,
    HeraldEffect $effect) {

    $key = "phragile:risk-rating";

    // Read existing value.
    $field_list = PhabricatorCustomField::getObjectFields(
      $object,
      PhabricatorCustomField::ROLE_VIEW);
    $field_list->readFieldsFromStorage($object);
    $field_list = mpull($field_list->getFields(), null, 'getFieldKey');
    $field = $field_list[$key];
    $field->setObject($object);
    $field->setViewer(PhabricatorUser::getOmnipotentUser());

    $risk = $field->getValue();
    $old_risk = $risk; // PHP copies arrays by default!

    // Add new value to array.
    $herald_args = phutil_json_decode($effect->getTarget());
    $risk[$herald_args['key']] = array(
      'value' => $herald_args['value'],
      'reason' => $herald_args['reason']);
    $risk_key = $herald_args['key'];

    // Set new value.
    $adapter->queueTransaction(
      id(new DifferentialTransaction())
        ->setTransactionType(PhabricatorTransactions::TYPE_CUSTOMFIELD)
        ->setMetadataValue('customfield:key', $key)
        ->setOldValue($old_risk)
        ->setNewValue($risk));

    return new HeraldApplyTranscript(
      $effect,
      true,
      pht(
        'Modifying automatic risk ratings (key: %s)!',
        $risk_key));
  }

}
```

Test Plan: Created a custom action for differential revisions, set up a Herald rule to match and trigger the custom action, did 'arc diff' and saw the action trigger in the transcripts.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: locutus, edutibau, ite-klass, epriestley, Korvin

Maniphest Tasks: T4884

Differential Revision: https://secure.phabricator.com/D8784
Fix an issue with Diviner symbol rule using incorrect logic

Auditors: btrahan
Move revision header warnings into custom fields

Summary:
Ref T5495. We currently show one warning in revision headers, about not having any reviewers.

I want to add a second warning (for missing Legalpad signatures). At least one install would like to add custom warnings (see T5495) which are so specific that we can't reasonably cover them in the upstream.

Generalize these header warnings by moving them to CustomField, so I can implement the Legalpad stuff without making a mess and the install in T5495 can use an extension.

Test Plan:
Hit all three header states, they look exactly like they did before this change:

{F173265}

Reviewers: btrahan, chad

Reviewed By: chad

Subscribers: epriestley

Maniphest Tasks: T5495

Differential Revision: https://secure.phabricator.com/D9793