Uses info from the diff to detect if files have been moved and displays the result in the diff viewer.

This adds the functionality of parsing git's extended header of detecting moved files. Before, the diff would show two changes: a deleted file and a new file. Now, there is only one change and it is displayed correctly in the diff viewer. Since a file may be moved and have no actual diff data (and no revision), some extra checks are now required to compensate for this. These may be different depending on the SCM, so a more generic approach might be required.

Using "git diff -M" to manually create a patch that contains:
-Files that have been moved and not edited
-Files that have been both moved and edited

(post-review has been updated but has not been posted yet, so to test you must manually create a diff)