Make the policy control a JS dropdown with icons

Summary: Ref T603. After thinking about this for a bit I can't really come up with anything better than what Facebook does, so I'm going to implement something similar for choosing custom policies. To start with, swap this over to a JS-driven dropdown.

Test Plan: See screenshot.

Reviewers: chad, btrahan

Reviewed By: btrahan

CC: chad, aran

Maniphest Tasks: T603

Differential Revision: https://secure.phabricator.com/D7285
Highlight the currently selected policy in the policy dropdown control thing

Summary: Ref T603. Make this a little easier to use by highlighting the current value.

Test Plan: See screenshot.

Reviewers: chad, btrahan

Reviewed By: chad

CC: chad, aran

Maniphest Tasks: T603

Differential Revision: https://secure.phabricator.com/D7289
Fix two issues where StandardPageView assumes it will always have access to a user

Summary: If we hit an exception very early, the request may not have a user yet. Don't assume it will.

Test Plan: Broke MySQL config on purpose to test some stuff, loaded Phabricator, got a nice error page instead of a super-fatal one.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Differential Revision: https://secure.phabricator.com/D7286
Improve an awkward initialization behavior in Javelin in Firefox

Summary: See comment; see IRC. This didn't cause anything bad, but ended up with `document.body.id == "null"` in Firefox, which is a bit weird.

Test Plan: Loaded page, put `document.body.null` into the console, got consistent results.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Differential Revision: https://secure.phabricator.com/D7288
Projects Icons Series 1

Summary: A set of random icons for use as project identifiers. 42, white.

Test Plan: photoshop, epriestley

Reviewers: epriestley, btrahan

Reviewed By: epriestley

CC: Korvin, epriestley, aran

Differential Revision: https://secure.phabricator.com/D7290