Balló György authored Oct 18, 2014 and Alberts Muktupāvels committed Oct 19, 2014

It was previously in gnome-settings-daemon.

Add new gnome-flashback-init application that will be autostarted
in Initialization phase. This will allow as to set some session
environment variables.

Currently it will be only used to set XDG_MENU_PREFIX.

1) Don't show dialog in taskbars and/or pagers.
2) Don't open dialog under other applications. Set it as 'always
on top' window.
3) Recreate dialog as GtkWindow. GtkDialog must have transient
parent, but we have no window to use as parent.
4) Make sure there is always only one open dialog. If dialog is
open and inhibitors changes just update dialog.

This can be turned off with GSettings:
gsettings set org.gnome.gnome-flashback draw-background false

Initially this application does nothing.