(CCCP Patch) CCCP LAV Filters' defaults.

Enable the mixer for now, as Lord had problems with
the Windows one. Maybe with NT6 we'll all be able to
disable this without thinking too much about it :V

Also enable the LAV Splitter's tray icon for testing for now.
(CCCP Patch) Make splitting force'able via a setting
(CCCP Patch) Stuff to make both build scripts work locally
(CCCP Patch) Make LAV Splitter prefer falling back on default tracks

By default, if there is no user preference, LAV Splitter will
prefer 'forced' tracks to 'default' tracks when falling back.
This can lead to fun things when coupled together with the extra
'forced subtitles' track created by LAV itself in case at least one
PGS subtitle track exists. Thus make LAV probe first for 'default'
tracks instead, and only then for 'forced'.