Clean up standalone parser toString ouput.

- quote identifiers
- add space between group bys for readability
- don't output position in aliases, just name.
- fix round trip unit test to deal with quoted identifiers.
- just output column name for StarSelect, not position.
Add support for mapping column names to the standalone-parser.
Merge pull request #1 from socrata/marcs/column-name-mapping

Merging.