Bug 888510 - In-content theming fixup for the new plugin click-to-activate. Remove the "lightweight" transparent click-to-play theming and make the normal styling plain grey. Switch from a CSS gradient to an image gradient because of performance issues. Highlight the "check for updates" button for outdated plugins. Icons by shorlander and lco. This branch patch does not include the new string which identifies the close button, so that button still works poorly in a screen reader. ui-review=lco r=jaws a=bbajaj

--HG--
rename : toolkit/themes/osx/mozapps/plugins/contentPluginCrashed.png => toolkit/themes/shared/plugins/contentPluginCrashed.png
rename : toolkit/themes/osx/mozapps/plugins/contentPluginDownload.png => toolkit/themes/shared/plugins/contentPluginDownload.png
rename : toolkit/themes/osx/mozapps/plugins/contentPluginMissing.png => toolkit/themes/shared/plugins/contentPluginMissing.png
rename : toolkit/themes/windows/mozapps/plugins/pluginProblem.css => toolkit/themes/shared/plugins/pluginProblem.css
Followup to bug 888510 - windowless-layers reftest should be skip-if no testplugin, not fails-if a=bbajaj