Refactor the fetched results controller and collection interaction.

[calebd]

I made the following changes:

• I think that performing two sets of batch updates in controllerDidChangeContent: is dangerous. At the end of the first update, the collection view could ask the data source for data that is now outdated which will cause a crash. I folded both update blocks into a single pass. #24
• I don't like the idea of using the mutable collections directly inside the change block since no garuntee is made as to when it will run. So, I copy the pending changes into stack variables and immeditely reset the mutable collections. This prevents the collections from being mutated in multiple quick passes through the fetched results controller methods. #24
• Added ability to disable change animations. #25
• Begin translating index paths from fetched index paths into view index paths. #24.
• Translate group indexes from fetched indexes to view indexes so that the appropriate groups are updated. #24

[calebd]

Can I do a version bump to 0.2.1 or should we wait for some more stuff?

[soffes]

I'll do 0.3.0 since the not found stuff could break things

[soffes]

Released!