Adding thickbox to dashboard for AJAX-y goodness.
Adding basic repo updating.

Adding an "Update" command to the Repo table inside the dashboard widget.
This command opens a thickbox where the RepoMonitor attempts to update a
repo.

Repo updating appears to work but should be treated as a beta feature.
Adding repo update status caching.

We now cache whether or not the repo has a dirty working copy. This way we don't need to re-scan all repos everytime the dashboard is loaded.
Added a helper function for scanning repos.

The helper function applies the proper scan for the repo type, saves the repo status, and checks whether the repo can be updated.
Adding nicer output formatting to the repo update page.
Adding post-commit hook to RepoMonitor.
Added realpath checking to RepoMonitor for relative paths.

Relative paths may now be given to RepoMonitor when adding and scanning repos. It uses the php `realpath` function to determine the absolute path to the repository.