Replace Sprite-Icons with FontAwesome

Summary: The removes the sprite sheet 'icons' and replaces it with FontAwesome fonts.

Test Plan:
- Grep for SPRITE_ICONS and replace
- Grep for sprite-icons and replace
- Grep for PhabricatorActionList and choose all new icons
- Grep for Crumbs and fix icons
- Test/Replace PHUIList Icon support
- Test/Replace ObjectList Icon support (foot, epoch, etc)
- Browse as many pages as I could get to
- Remove sprite-icons and move remarkup to own sheet
- Review this diff in Differential

Reviewers: btrahan, epriestley

Reviewed By: epriestley

Subscribers: epriestley, Korvin, hach-que

Differential Revision: https://secure.phabricator.com/D9052

src/applications/conpherence/controller/ConpherenceController.php

@@ -40,13 +40,13 @@ abstract class ConpherenceController extends PhabricatorController {
         id(new PHUIListItemView())
         ->setName(pht('New Message'))
         ->setHref($this->getApplicationURI('new/'))
-        ->setIcon('create')
+        ->setIcon('fa-plus-square')
         ->setWorkflow(true))
       ->addAction(
         id(new PHUIListItemView())
         ->setName(pht('Thread'))
         ->setHref('#')
-        ->setIcon('action-menu')
+        ->setIcon('fa-bars')
         ->setStyle('display: none;')
         ->addClass('device-widgets-selector')
         ->addSigil('device-widgets-selector'));