Notify: new semantics and name for hidden/muted packages.

Change ownership of hide files form pkg-build to user. Rename
visible commands from hide to mute. Finalize mute/hide semantics:
a muted package stays muted until unmuted, irrespective of
package state. Use always available /var/tmp instead of LPF_VAR/tmp.
update: Use fixed font in 'update done' dialog.
update: bugfix: handle window delete signal.
TESTING: update
notify: notify-watch: kill other running instances, bugfix

inotifywait sometimes completes with an error code; ignore this.
notify: Don't trigger new message when just updating state.
pkgbuild: use local, remove dead code, quoting, comments.
scripts: comments, cleanup, pylint fixes.
lpf, README: enhance help message, doc update.
Adding gnome appdata.