Miniturize the nav buttons

Summary: This uses the slightly smaller icons. Not sure about the logout icon, will play with it more in the morning.

Test Plan: tested new nav on desktop and mobile.

Reviewers: epriestley

Reviewed By: epriestley

CC: Korvin, epriestley, aran

Differential Revision: https://secure.phabricator.com/D8119
Add app icons to quick menu

Summary: This adds the app icons, cleans up css Ref T3623

Test Plan: see new icons in dropdown menu

Reviewers: epriestley

Reviewed By: epriestley

CC: Korvin, epriestley, aran

Maniphest Tasks: T3623

Differential Revision: https://secure.phabricator.com/D8124
Merge remote-tracking branch 'upstream/master' into release