[packagekit] gnome-packagekit development

[Richard Hughes]

In readiness for moving upstream development to GNOME.org, I've been
cleaning up the codebase this morning. Notable changes include:

• Remove the libglade dep, we now use GtkBuilder
• Remove the libsexy dep, and make the dep on gtk+ to be 2.15.0
• Make the dep on unique hard, and remove all the ifdefs
• Make the dep on gio to be 2.18.0, and remove the ifdefs
• Remove gpk-update-viewer, and rename gpk-u-v-2 to gpk-u-v

Of course, all these changes make things almost impossible to backport
gnome-packagekit back into stable distros, and I apologize for that.
2_27_X is a unstable series and these sort of changes are to be
expected.

Of course, sticking to the GNOME development freezes for
gnome-packagekit, also means the distros can do the release planning in
the usual way, just like all the other GNOME modules.

Richard.