Add mol_to_ctab(mol, bool default true) to Postgres cartridge.

	* Tested on Postgres 9.x only. Should however work on 8.x too.
	* Tests require fix for issue #229 to complete successfully.
Merge pull request #230 from janholstjensen/pg-add-mol_to_ctab

Add mol_to_ctab(mol, bool default true) to Postgres cartridge.