Fixed up creating content so that after creation it re-routes back in to edit mode so we don't just keep the 'create' flag. This caused some issues with validation because after creation the edit page needs to re-bind the entity from the server and previous to now that means that the server validation collection would have been cleared. We now persist the collection and it's up to the controller to re-bind if necessary.
Fixed validation problems when creating new content without the absolute mandatory values needed to create something (like name)
Adds RequiredForPersistenceAttribute to easily detect if any entity fails validation in a way that it cannot be persisted to the data store. Changes all tree events to not be jquery events and to not require a 'callback' jquery object, instead we just use angular events broadcast globally, much nicer.
Merge branch '7.0.0' of https://github.com/umbraco/Umbraco-CMS into 7.0.0