Add extractors for Riak KV datatypes.
Add datatypes fields to the default schema.
Add riak_test for datatype extraction.
Fix bad format in yz_solr_proc.
Fix some bugs.

* Extractor registrations have to be sorted.
* There's a tiny delay (about 1s) in committing to Solr, so we have to
  use rt:wait_until/1 for the queries.
* URL-escape fields and terms in search queries going over HTTP.
* Cleanup whitespace
Change register fields to stored.
Merge pull request #250 from basho/feature/sdc/crdt-extractors

Add support for KV datatypes (counters, sets, maps)