Summary: Ref T10390. Fixes the missing "fa-dashboard" icon and adds a few more for an even 25.
Test Plan: Create new dashboard, see dashboard icon, select new dashboard icon.
Reviewers: epriestley
Reviewed By: epriestley
Subscribers: Korvin
Maniphest Tasks: T10390
Differential Revision: https://secure.phabricator.com/D17526
Summary: Allows users set an icon (for reuse on upcoming home) for their dashboard based on 16 descriminating choices.
Test Plan: Create a new dashboard, set new icon. Edit an existing dashboard, set icon.
Reviewers: epriestley
Reviewed By: epriestley
Subscribers: Korvin
Differential Revision: https://secure.phabricator.com/D17042
