Updated merb-thor tasks

Lots of questions have come up regarding sake in #merb recently. The current sake tasks at merbivore.com are out of date, so I updated the tasks inside merb-more itself. You can install using:

http://github.com/jackdempsey/dm-thor/tree/master

For those interested in Thor, I've also updated the tasks at:

http://github.com/jackdempsey/merb-thor/tree/master

They, like the sake tasks, are particular about directory structure, so make sure you've set things up, and run things from the correct directory.