Cleanup wrongly imported packages

This should create a clean package that can be installed from this git repo (and included in our requirements.txt)

* openid and simplejson were just old versions of python-openid and simplejson.  New ones from pypi (via pip) work just fine
* opensocial wasn't used by the module itself, and the project appears to be semi-abandoned, so I just deleted it (also, this was added after the package was uploaded to pypi)
* oauthlib appears to have been derived from opensocial (or opensocial's oauth code was pulled from the same really old oauthlib, I haven't gone spelunking through oauthlib's repo).  Given that it doesn't at all line up with the current oauthlib library, I moved it into the yahoo/ directory to keep it in yahoo's namespace (which although it's still a dirty hack, it's better than leaving it).