Update riak to 1.4.2.

riak-1.4.2:
- Fixed various problems related to crashing stats
- Fixed extra noisy logs introduced in 1.4.1 (Not found errors and others)
- Fixed issues related to 2i queries timing out
- Added more protection against corrupt data in backends
- Fixed incorrect capability negotiation causing nodes to appear incompatible
  in Riak Control

riak-1.4.1:
- Pagination for equality queries is fixed by riak_kv/615.
- The ability to set a timeout on a 2i query has been added by riak_kv/616.
- Using 2i as input for a map-reduce job has been fixed by riak_kv/618.
- Riak Control can crash its host node when in a mixed-cluster environment
  containing a 1.4.0 node. This has been addressed by riak_control/120.
- Basho's leveldb fork has added better fadvise support and fixed some race
  conditions in the write path. See leveldb/88.