Railtie to pull in Rake Tasks

Hi Ludicast,

I'm new to both Rails and Github, so pardon me if this is the incorrect way to approach this.   I modified the yaml_db.rb file to include a Railtie that loads the Rake tasks.  This way, you don't have to do that first step int he README file and can begin using yaml_db as soon as you install the em. If that's in any way helpful to the project, feel free to use it.

Thanks,

Justin