Use the 1.4.4.0 riak_pb package.
Add 2I term regexp feature from 1.4.4+

This targets the 2.0-stable branch and should be ported to master/Riak
2.0 as well.
Fix some lingering internal uses of RiakClient.solr.
Merge pull request #292 from basho/feature/sdc/2i-term-regex

Add 2I term regexp feature from 1.4.4+