Replace more direct XFixes usage with a the appropriate abstraction
API from mutter, which is guaranteed to work in wayland too.
It doesn't yet replace pointer position tracking, although probably
it should.
Also, because now we're using Mutter API, we lose the standalone
test case.
https://bugzilla.gnome.org/show_bug.cgi?id=705911
This will replace the indicator painted on the stage right now.
This unfortunately does not work for the recorder triggered by the
keybinding -- we'll simply replace the in-shell code with a keybinding
powered by gnome-settings-daemon.
If we are passed an invalid file template, ShellRecorder.record()
will return a %NULL filename; as the Screencast DBus interface
expects a string return value, we cannot return the value unmodified
in that case.
https://bugzilla.gnome.org/show_bug.cgi?id=700842
Like screenshots, the screen recorder can be a useful tool in other cases
than being triggered by a keyboard shortcut. To account for that, export
a Screencast DBus API similar to the existing Screenshot interface.
https://bugzilla.gnome.org/show_bug.cgi?id=696247
