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
Of course it has to be run, but we need to figure out a reliable way to handle warnings.
One seems to be the detection of anything being printed to `stderr`.