Initial work in progress query rewrite support.

Currently supports matching columns, literals and count(*) in the selection
and columns in grouping.
Cleanup query rewrite support and added support for limit/offset in query.
Pull out SoQLTypeCodec and make RollupInfo use AutomaticJsonCodecBuilder for the win.
Clean up code by using a flatten and fix an Anal type.
Small code review tweaks to query rewrite.
Merge pull request #6 from socrata/marcs/rollupquery

Initial query rewrite support.