Fix media-sound/pavucontrol 1.0

This requires gtkmm:2.4, which is now properly expressed.
Update sys-devel/pconfigure to 0.2.0
Add x11-plugins/gtalk-shared-status at 0.2.5

This is a super-simple ebuild: it doesn't even have dependencies!
Update app-text/mupdf to 1.2
Remove some unused packages