Uninstaller: MonoDevelop is not uninstalled from Windows.

When running the uninstaller on windows xp, all files in the install dir is removed except the MonoDevelop directory.

Repro
1. Install Unity on windows
2. Uninstall Unity on windows

Result:
The MonoDevelop directory is not removed from C:\Program Files\Unity\

Expected:
All files installed with Unity's installer should be removed when the uninstaller is run.