Lots of updates

- Added NetworkActivityIndicator setting method and isReachable to DNApplicationProtocol
- Reworked DNCollectionView batch update animation processing
- Tweaked DNCommunicationsAPI to add isReachable check and NetworkActivityIndicator calls
- Added override method 'addedAttribute' to DNManagedObject
- Added getAllFromID to DNModel (to receive and look for duplicate ID's
- Added shouldChangeObjectUpdateHandler call for CollectionViews that have the individual cells watching for content updates making the main updateHandler calls unneeded
- Added multi-section groupBy option to watchFetchedObjects
- Updated podspec version

Signed-off-by: Darren Ehlers <me@darrenehlers.com>