R1:ddd7cbb698cf

Add setImage to PHUIActionPanelView

Summary: Additonal option to use newly made images in these views.

Test Plan:
Built an example in UIExamples.

{F5071682}

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin

Differential Revision: https://secure.phabricator.com/D18299