Add ANTLR 3.5 and regenerate grammars. Begin to fix ensuing compilation problems.
NH-3251: Fixed compilation failures and then many test failures due to trying to convert non-terminals to roots.
NH-3251: Fixed more test failures due to the root promotion bug.
NH-3251: Fixed not implemented exception relating to HQL parsing.
NH-3251: Removed a bunch of useless code.
NH-3251: Fixed the last two discriminator test failures.
Merge branch 'patearl-NH-3251'