Implement sharding distribution model using `jumping consistent hash` on top of `gproc`

[Carlos Andres Bolaños R.A.]

Currently riak_core is used as distribution tool, to implement different distribution models (sharding, sharding + peer-to-peer replication, etc.) on top of gproc. The idea is to implement something simpler, a 1st approach may be only support sharding, using jumping consistent hash (http://arxiv.org/ftp/arxiv/papers/1406/1406.2294.pdf) on top of gproc.