Implement Google Bigtable API

[sashaafm]

Add a wrapper for the Google Bigtable API.

[sashaafm]

Since there's the possibility of Datastore being implemented via Diplomat (which is being developed at the moment) I think I will give a higher priority to Bigtable in order to get work done on both fronts at the same time.

I'm scheduling to start working on this in September.