Modify synctree hashing to enable future extension
Modify synctree hashing to enable future extension

This commit adds a single byte to the data encoding for bucket hashes to
enable easy future extension of the data format to support different
hash functions.

ricardobcl/riak_ensemble,basho/riak_ensemble,sargun/riak_ensemble,sargun/riak_ensemble,cmeiklejohn/riak_ensemble,basho/riak_ensemble,cmeiklejohn/riak_ensemble,ricardobcl/riak_ensemble