Add a meta-application

Summary:
  - Adds a new "Applications" application.
  - Builds an application list via application config instead of via hard-coding, so we can move toward better concepts of installing/uninstalling applications, etc.
  - Applications indicate that they need attention with notice counts and brief status messages rathern than 50 giant tables of all sorts of app data.

I want to try replacing the home screen with this screen, pretty much. Not sure if this is totally crazy or not. What does everyone else think?

Test Plan: Will add screenshots.

Reviewers: btrahan, chad, vrana, alanh

Reviewed By: vrana

CC: aran, davidreuss, champo

Maniphest Tasks: T1569

Differential Revision: https://secure.phabricator.com/D3129

src/applications/fact/application/PhabricatorApplicationFact.php

@@ -18,6 +18,18 @@
 
 final class PhabricatorApplicationFact extends PhabricatorApplication {
 
+  public function getShortDescription() {
+    return 'Analyze Data';
+  }
+
+  public function getBaseURI() {
+    return '/fact/';
+  }
+
+  public function getIconURI() {
+    return celerity_get_resource_uri('/rsrc/image/app/app_fact.png');
+  }
+
   public function getRoutes() {
     return array(
       '/fact/' => array(