Simple setup

I've made some changes to the database configuration. Basically, it allows you to set up the project much smoother. The `database.yml` file is no longer part of the git repo. Instead, you are asked to copy `database.yml.example` and setup your own config. And I added SQLite as the default dev database to allow people to get up and running quicker.

@lencioni, @paradasia, @ted27, before you pull the latest changes from github next time, you might want to make a copy of your current `database.yml` - it might get removed by git when updating (though I'm not entirely sure what happens to a file that was previously part of the repo, but now in .gitignore).

Something like...
```bash
cp config/database.yml config/database.yml.bkup
git pull --rebase
mv config/database.yml.bkup config/database.yml
```
...and you should be good to go. Let me know if you run into any issues.