Moved scaffold-faces to javaee addon
Cleaned up the ScaffoldProvider SPI.

Also converted the scaffold-faces addon to a maven submodule.
Enhanced the ScaffoldProvider SPI with an isSetup() method.

This is used to indicate whether a provider was setup in a given
setup context.

Also enhanced the scaffold addon test to verify for scaffold setup.
Added test to verify the generation contract of ScaffoldProvider

A Mock scaffold provider that scaffolds mock resources has been
created.
Removed Faces Scaffold addon from Core.

This addon is now present in the JavaEE addon.
Hence, we'll include it just once.
Fixed generation logic to use JavaResources instead of JavaClasses.

This ensures that the scaffold provider design to use Resource
instances is upheld. It removes the restriction on using JavaClass
instances to represent 'scaffoldable' items for a scaffold
provider.
Modified ScaffoldProvider API.

This adds Project as a parameters to the getSetupFlow() and
getGenerationFlow() methods of the ScaffoldProvider interface.
This ensures that the selected Project instance can be accessed
in these methods.
Aggregate all setup commands into a single dialog.
Modified the ScaffoldProvider API to return NavigationResults.

This now requires all scaffold providers to construct the
navigation entries themselves instead of depending on the
scaffolding addon to do so. It ensures that the wizard pages are
more accurately constructed especially if they happen to be
composite commands.