Bug 1014332 new about:providerdirectory page that appears in share panel, r=jaws

--HG--
rename : browser/themes/osx/aboutSocialError.css => browser/themes/shared/aboutSocialError.css
Bug 1014332 error page fixes for share panel and about:providerdirectory support, r=jaws
Bug 1014332 share button CUI widget, r=jaws
Bug 1014332 activation support for share panel, r=jaws
Bug 1014332 test cleanups that better address some async issues, r=jaws
Bug 1014332 fix share context menu tests, r=jaws