Allow the Disk I/O Storage Group scheduler to fallback to free space

The "Balanced Disk I/O" Storage Group scheduler was indeterminate when
the weights of two filesystems were equal.  This commit makes that
decision more determinate by allowing the scheduler to fall back to using
the amount of free space on the filesystems to make the decision when
two filesystems have the same weight.

Closes #10946.

Signed-off-by: Chris Pinkham <cpinkham@mythtv.org>
One more fix to allow Theme Chooser to treat devel/* as master.
Remove unused FreeSurround class member

Coverity-Id: 700822
Coverity false positive..

sample_spec is initialised properly before being used in AudioOutputPulseAudio::OpenDevice()
buffer_settings is initialised properly before being used in AudioOutputPulseAudio::OpenDevice()

While at it, simplify call to pa_channel_map_init_auto; it returns a pointer to provided channel_map ; so no need to save it

Coverity-Id: 746856
Merge remote-tracking branch 'upstream/master'