CocoaPods and build.sh updates

- Updated podspec to support both iOS & OSX
- `clean` now removes all non git-versioned files (except `core/`)
- added `browser` target
- added `deploy` target
- added `pod-deploy` target
You and @timanglade certainly know more about the website's deployment process than I do, so I'll refer to you guys for the best way to do this.