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?
Ah, good point. Yeah, I don't want to screw with GetMulti right now because I remember there was some other issue, but I'm fuzzy what it was.