Changes touching the build:
- Bumped version to 0.5.0.
- Removed dependency on Xfce libs (it only depends on GTK+-2.0.)
- Updated Makefile with new source files.
- Build ChangeLog through a script (remove it from source tree.)
More generally speaking, the interface is build on top of a GtkBuilder
UI definition, with a personal GtkTreeView and a Settings GObject to
update the information shown on the interface on changes. All the code
is being written with GObjects which will make it a lot easier to
separate GUI code and system code.
