Added CUBRID Database 8.4.3+ support.

PR for #317: **Add support for CUBRID Database**.

Tested on custom projects. Reverse and Forward engineered **demodb** demo database which is supplied by CUBRID by default. All successful.

Could not run Propel2's own test suits because of the way these tests are created. Issues with Propel2 test suits are [here](https://github.com/propelorm/Propel2/issues/317#issuecomment-10878695) (CUBRID doesn't provide anything like disabling the foreign keys. Propel2 creates table with no order, i.e. child tables before parent tables, which cause errors) and [here](https://github.com/propelorm/Propel2/issues/317#issuecomment-10941834) (in CUBRID database names must be 17 characters or less. Propel2 uses 18+ characters). Until these issues with test suits are fixed, Propel2 tests can't be run on CUBRID Platform.

Other than that, I have successfully used CUBRID with Propel2.