Add base gtk# md addin

[harry-cpp]

This adds the base gtk# addin for MonoDevelop. It currently posses the following options:

• Project templates (C#):
  • Gtk# Application
• File templates (C#):
  • Window template
  • Dialog template
  • Widget template
• Glade file integration

On my TODO list for this addin there are only F# templates remaining, so if you think of something else that is missing, do mention it.

[thiblahute]

OK, we should document those stuf at some point :-)