fix to 'properly' process whole list of sources (on autoplay = on)

instead of failing / stop processing list on url decode
not being successful 

fix alone is line on line 521 (rise exception) . 
following this change I changed calls to PlaySource (line 466 and 2295) to ignore this exception in case it would rise (original code was expecting correct return from it).
(in case there are calls to PlaySource() from other scripts outside default.py, those needs to be changed as well - I have not checked whole source)