Merging-in new versioning scheme

Hi everyone!

I'm switching this package over to using Gustavo Niemeyer's new gopkg.in service.

This will allow old versions of the api to be served VIA a much cleaner mechanism than the old subdirectory mechanism. What was once `import "github.com/cookieo9/resources-go/v1/resources"` is now `import "gopkg.in/cookieo9/resources-go.v1"`.

The previous versions are now held in branches (as they should be), but those branches are now go-gettable.

As a result the repo has changed as follows:
  - There are no longer versioned subdirs (content moved to branches)
  - The master branch (github.com/cookieo9/resources-go) is the development branch
  - Each branch is tested separately
  - Although lower priority, fixes and backwards compatible changes to older versions are still possible

What this means for you:
  - If you have code that depends on a specific version of the API, you simply change the import paths in your code (as shown above), and the code should be stable for the forseeable future.
  - If you are writing new code, use the new gopkg.in paths (preferably v2)

This change doesn't mean that resources-go is back in development, just that any future development will be to a completely separate branch from the stable v1 and v2 branches.

This merge will happen in a few days, in case anyone has comments, criticisms, or questions. To see what the development repository (master) will look like, check out the dev-gopkg.in branch. The v1 and v2 branches are live, and can be go-getted via their new urls.