Update RoleControl::Controlled to dispatch on target type

+ Close issue #330
+ Add specs for case of creating a project with user_group owner
Merge pull request #334 from edpaget/fix-user-group-ownership

Update RoleControl::Controlled to dispatch on target type
fix serialised resource responses
rework generic create / update actions for controllers
standardise updatable resource responses
Merge pull request #335 from camallen/projects_create

Fix incorrect RestPack serializer usage