Adding TDS (aka Microsoft SQL) to dialects.

Hello! I'm working on an ETL project that uses node-orm2, which utilizes your query library. I would like this project to be able to talk to Microsoft SQL via Tedious to get the widest SQL coverage available. In order to do that, I need node-orm2 to talk to MSSQL---and in order to do /that/, I need node-sql-query to speak its dialect.

Since the library itself is pretty well organized, it was fairly trivial to add a dialect for MSSQL. I'm submitting this pull request so that others might benefit. I've also created a unit test module for the new TDS dialect (based on MySql) and made sure it passes all checks.

Hopefully this will help you guys out. If there's anything you need from me to accept the request, please let me know. (Or if you just want to reject it outright, I guess that works too!)