Removed from Serialization/Type.cs Set and Collection, using List for both
MessageAttribute now requires a guid.
Removed IProject.
Added Guid to MessageAttribute constructors.
Changed IProjectManager property Projects to method GetProjects.
Changed message ProjectUser's properties setter accessors to public.
Removed repeated code.
Removed Mono.Addins reference from Editor.Client.
Removed RPCGen from Editor.Shared.
Changed ProjectManager property to method.
Added PackageGen entry point.