Feature/add gomemcache

Add optional golang based gomemcache library. 
This library does not require libmemcached, and provides it's own pooling, but does not offer the level of control that gomc does. This library has NOT yet been fully load tested.

@bbangert || @kitcambridge r?
Since the Unregister function is not strongly supported by the server, storing the "delete" is less important. That said, the warning log is missing from this (possibly due to the munged merge) I will add it back in.