[platform-ui-dev] Colors API

[Kim Horne <Kim_Horne@xxxxxxxxxx>]

The initial implementation of the platform
UI colors API has been released.  This API is analogous to the existing
fonts API in that it provides a registry (see org.eclipse.jface.resource.JFaceResources.getColorRegistry())
 from which instances of defined colors may be obtained and the org.eclipse.ui.colorDefinitions
extension point which plugins may use to define them.  Additionally,
there is now a Colors preference page located under the Workbench page
which allows user customization of colors.

Although the API is in place and relatively
complete (see Bug 48745), the workbench does not yet utilize it for its
own color needs.  This will come for subsequent builds.