Avoid cancelling self._gc in PBCTransport if it has already been cancelled.
Merge pull request #30 from jerith/fix-pbc-transport-cleanup

Fix PBCTransport cleanup on pypy
Implement client.ping
Implement get, ping and delete
Implement put
I can't even understand how to implement this...
Clean some unused dependencies
Merge branch 'master' of github.com:calston/riakasaurus