Log Message:
Update riak to 1.4.6

Changes since 1.4.2:
* Secondary index improvements
* bitcask/122:   [Bound merge queue to number of partitions]
* node_package/101: [Add extra options to debuild template]
* node_package/93: [Incorrect package format in SmartOS causes segfault
  on pkg_info]
* riak_core/429: [Handoff fix is to enable handoff to complete in mixed
  pre-1.4 clusters]
* riak_core/467: [Bound the time that stats calculation can take]
* riak_core/470: [Provide a synchronous registration and unregistration
  of services.]
* riak_core/476: [Remove connection manager and service manager.]
* riak_kv/715: [2i term regex filter 1.4]
* riak_kv/743: [Fix vnode sending > max_results items for 2i query]
* riak_kv/766: [Fix error when hashing index data in tree builds]
* riak_kv/767: [Fixed 2i queries in mixed clusters]
* riak_kv/772: [Fix broken return terms handling]
* riak_kv/774: [Enable bloom filters for AAE LevelDB instances]
* leveldb/110 [Add option for changing fadvise
* leveldb/112: [Create asynchronous close path to resolve race between
  write threads]