Removed REGIONS conditionals.
Re-enabled DefaultRegionManagerAccessor usage of RegionManager.
Added file that belonged with commit/revision 6a317c609528dab8a459cc6f1fe67a4dff5db29c.
Removed commented out namespaces.
Fixed formatting to match Prism original file.
Removed REGIONS conditionals from Prism.MefExtensions.WinForms.