v1.5 Release

We're getting close to completion so time to open a pull request.

Here's an outstanding list of things to do:

- [x] Review documentation
- [x] Create release notes (#122)
- [x] Update README (see #126)
- [x] Fix SocketRocket dependency to a known tag/fork rather than HEAD
- [ ] Create some pre-compiled binaries

After merge, we will need to:

- [ ] Add new Podspec to the CocoaPods specs repo
- [ ] Check generated documentation on CocoaPods.org
- [ ] Create release on Github with release notes and binaries