Add CRDT stats to get FSM and client APIs

* Change riak_kv_crdt:value/2 to return stats about the datatype as
  well.
* Send the CRDT Mod into the get FSM so we know what kind of datatype
  is being fetched when we record stats.
* Add the CRDT module into the get_fsm stat update and parameterize
  stats by whether a CRDT was used.
* Record pure CRDT stats like actor_count outside the FSM.
Fix kv_crdt_eqc module.
Fix riak_kv_crdt:eqc_test_/0.
Add CRDT stats to put FSM
Add timing and counters for CRDTs to vnode
Added CRDT Stats
Change application:get_env/3 to app_helper:get_env/3.
Fix bad pattern-match in CRDT stats code.
Rename vnode_dt_merge stats to general object merge stats