Glock client to handle multiple glock servers using consistent hashing

@treeder @edsrzf 
TL;DR: 

To test this branch, please open up three terminal windows
./glock
./glock -p 45626
go test


Using consistent hashing as a hash table

Glock Client will handle multipel glock servers, if one server drops
due to a connection error, the client will drop the server from its
consistent hashing list. And then recursively attempt to lock again.

All consistent hashing calls are already protected by a lock inside the
library so we don't need to do any mutex locking while using them.