SQLite3 Adapter

## SQLite3 Adapter

First of all, I'd like to thank the Sails.js team for creating such an amazing framework. I ended up creating a SQLite3 adapter for Waterline because I needed a lightweight database that was going to run on an embedded device (BeagleBone Black) and it seemed like there was no support for it.

Again, special thanks to the developers and community of Sails.js and Node!

### Important Note

**Please do not merge this yet** as the code is definitely not ready for primetime. None of the unit tests have been written for it and lot of the code was loosely based on the PostgreSQL adapter which may or may not cause problems with SQLite. I am submitting the pull request to let everyone know that the SQLite adapter is under active development and to eliminate duplicate efforts (and possibly get some helping hand on my end).