Add Support for Derby

[lonnyj]

I started writing an extension for Liquibase. GeoDB came in useful for H2 but I'd also like to support Derby. I forked the project and have a version that works for both H2 and Derby. If possible, I would like to contribute this back to the main project once it is ready. This is my first time doing such a thing so recommendations are welcome.

[jdeolive]

Wow, this looks great! This contribution would be awesome! I will try to review as soon as I can. So if you could submit your changes a pull request that would be great. If you plan to do other work on your master branch I would recommend you first create a branch for this work and then submit that in the pull request. Looking forward to this!