Supporting Multiple Databases

[bhauff]

Hello,

I added a few small changes and some documentation in the README to support multiple databases per environment in sequel-rails. There is a caching mechanism that makes sure you connect to a database when you first request it, and then for subsequent requests it is reused. I worked on this with Jeremy Evans a bit. In the future it would be good to support nesting multiple databases under each environment. For now I just implemented supporting multiple top level databases. Let me know what you think!

Thanks,

Brandon Hauff