Mousepad Improvements

[Matthew Brush]

Hi all,

I recently started messing around with Mousepad on my own Git 
repository[1].  I've added some new features:

* Support for GtkSourceView by using "--enable-gtksourceview" for the 
./configure script.  Without using this option, Mousepad works exactly 
like before except for the last item in this list.

* Support for Gtk+ printing using the GtkSourcePrintCompositor.

* Three new items in the Options menu:
   - "Color Schemes" to choose the GtkSourceView colour scheme
   - "Filetype" to choose what language the GtkSourceView highlights
   - "Advanced" to set the GtkSourceView properties like tab width, 
highlight current line, etc.

* Auto-detection of filetype on open.

* Use GKeyFile for saving/loading config file.

I've put a screenshot of the UI here[2].  The code still needs more work 
but it's quite usable so far.  Feedback would be appreciated.

[1] https://github.com/codebrainz/mousepad/commits/gtksourceview/
[2] http://imageshack.us/photo/my-images/560/mousepad.png/

Happy Coding,
Matthew Brush