Sync Manager for iOS (work in progress)

Half-way there - but it's probably best to get review/feedback early

- projects dependencies updated
- plugin mostly implemented (in some cases calling methods that don't do anything yet, no events fired in webview yet for sync updates)
- sync down implemented for soql targets (sync status is updated in database but no notifications sent out yet)
- sync up: not started
`target` is an unfortunate term [overload](https://developer.apple.com/library/ios/documentation/general/conceptual/Devpedia-CocoaApp/TargetAction.html) in iOS;