Updated version of the aggregate order by patch.
Includes docs + regression tests all in the same patch.
Changes:
- removed SortGroupClause.implicit as per review comments,
replacing it with separate lists for Aggref.aggorder and
Aggref.aggdistinct.
- Refactored in order to move the bulk of the new parse code
out of ParseFuncOrColumn which was already quite big enough,
into parse_agg.c
- fixed a bug with incorrect deparse in ruleutils (and added a
bunch of regression tests for deparsing and view usage)
- added some comments
--
Andrew (irc:RhodiumToad)
