New icons for Maniphest

Summary: Fixes 2x white icons, adds 'user' and 'project' icons.

Test Plan: tested new states in Maniphest

Reviewers: epriestley, btrahan

Reviewed By: epriestley

CC: Korvin, aran

Differential Revision: https://secure.phabricator.com/D7176
Merge branch 'modifications'

Conflicts:
	webroot/rsrc/css/phui/phui-document.css