Bump client version and riak_pb dep for Riak 1.4 features.
Unify the bucket properties tests since PBC will support all properties.
Add support for all bucket properties and clearing in PB.

Also, some code reorganization was done in codec.py, translate_rw_val
was renamed to _encode_quorum.
Add some much needed documentation for other PB codec methods.
Cleanup bucket properties shortcuts with a helper function.
Use the search property instead of directly modifying precommit.

The bucket fixup for search has been available since 1.0, it is much
cleaner and more reliable to use it instead.
Fix a few doc string problems in bucket.py.
Predicate the bucket properties features on version detection.
Apply some PEP8 and pyflakes fixes.
Merge pull request #256 from basho/gh256-1.4-bucket-props

Riak 1.4 Feature: Protocol Buffers Bucket Properties