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?
Yup, the comment is wrong; nice catch! I was referring to the `result = *new(ChannelIDs)` line specifically—could it be removed entirely? Since `result` is a named return parameter, I think it's already initialized.