Git deploy should allow multiple sites in a single repo

[preaction]

Right now, since the Git deploy requires you to give the exact path to the Git working directory, the only way to have multiple sites is for them all to share the same space, which will lead to conflict.

The Git deploy should search up the tree for the .git directory and use that as the working tree, allowing multiple sites in the repository.

This will let us build example sites for the default theme set, which we will need.