A few improvements for Xcode 6+

Bumps version to 0.5

- Removes support for waxsim
- Unifies configuration of Cedar Spec Suites and Cedar/iOS/OSX test bundles in thrust.yml (breaking configuration changes)
- Fixes hardcoded bundle test destination which was broken in Xcode 6+
- Allows bundles to be built for architectures specified in Xcode project (removes hardcoded ARCHS flag)
- Adds support for specifying an alternate path to ios-sim