Add test for multiline statements
Add test for insane input to CDB_QueryStatements
Rewrite CDB_QueryStatements in plpython

Reduces the time to answer to the insane input test from over
one minute to a few milliseconds.

CDB-1797 #resolve
Simplify regexp

It's been tested against python 2.6.5 and 2.7.5, hopefully
2.7.3 (travis) will also be happy
Merge remote-tracking branch 'origin/fix/CDB-1797'