Allow for drush make-driven development, site folder git repos.

One of the biggest requests for DevShop has been site-folder-repos and drush make driven development and deployment.

I'm sold. Let's make this happen.

What if we store a "makefile URL" property on projects. It could be a link to the raw source code on drupalcode.org or github. Then we could build the platforms from that.

We would then have to store a Git URL for each environment.

Hostmaster creates the sites/mysite.com folder automatically, writing over settings.php and creating the files folder.

We could run a post hosting task hook to git init that folder, and then `git remote add` and `git pull`. As long as the .gitignore ignored the settings.php and files folders, I think this would work pretty well.

I also want to make a new task called "Deploy". This would create a New Platform for the chosen tag/branch and then Migrate the site properly using aegir. Do do this I would need another table to keep track of all the platforms for an environment.

This should open things up for people that work this way.

Thoughts?