Upgraded to latest iOS Mixpanel SDK

* Enabled ARC support and resolved issues
Merge branch 'master' of github.com:hyperlab/TiMixpanel

Conflicts:
	ios/titanium.xcconfig
Fixed: device token is not correctly send to Mixpanel
Added updated version to dist/ folder, updated readme and manifest
Merge pull request #9 from timanrebel/master

Release 0.5

- Upgrade Mixpanel iOS SDK to version 2.5.0, adding support for A/B-tests
- Fix device tokens not being correctly sent to Mixpanel (for push notifications)