Submodule support

I have been using WebGitNet for a while. Thanks for your work!

I noticed that repositories with submodules cannot be displayed. I have started working on a fix. I would like to get your feedback before I get too far along.

Here is a screenshot of the changes I made. Basically, it just adds the hash to identify this as a submodule rather than a folder regular folder. It would be nice to add some styling to set it apart even more (suggestions?).

![Capture](https://f.cloud.github.com/assets/963645/37522/b7d3b422-546a-11e2-8e1d-d9a20b34b391.PNG)

Also, submodules are not completely browsable yet - just the first level. Again if you have any suggestion on a good way to do this, I will give it a try.