Notifcation icons for Conpherence

Summary: Adds notification icons for Conpherence and re-writes the CSS a bit for the new icons and states. I removed the background bubble here and went straight CSS. I also seem to have a JS error and the notification menu doesn't display, but I'm tired and wanted to look at this in Differential. Will update after JS fix.

Test Plan: Turned on notification numbers and conpherence numbers, turned them off. Made them big. Checked FF and IE.

Reviewers: epriestley, btrahan

Reviewed By: btrahan

CC: aran, Korvin

Maniphest Tasks: T2415

Differential Revision: https://secure.phabricator.com/D4666