Cleanup capabilities and repository API

• Type: Story
• Status: Closed
• Priority: Minor
• Resolution: Completed
• Affects Version/s: None
• Fix Version/s: 7.0.0 M4
• Component/s: Document Repository Framework, Documents & Media
• Labels: None

Solve some of the problems with the current repository API and implementation:

• Remove dual interfaces Repository/LocalRepository

• Now that the capability API is more stable, clean it up and refactor the implementation.