currently, the orientation of group modules is always the opposite of
the bar. Change it so that:
* the default orientation of the group module is always the opposite of
its parent, even for nested groups
* the orientation can be overridden in the config
* css ID and class are set for the group element
when the module fails to get the pulseaudio device form factor, the
module persists the existing value, resulting in the incorrect
format-icon being used to format the label on device changes.
reset the form factor value so that the icon lookup properly falls back
to "default" when missing
Reading brightness value for backlight device can fail intermittently
(particularly when using ddcci-driver-linux). Handle this more
gracefully rather than crashing