Apparently, since 'setlocale( LC_NUMERIC, "C" );' was removed from
libvlc initialization 3 years ago, the syntax to set configuration
variables of floating point types has changed and become dependent
on the current locale ("0.5" vs. "0,5" etc). Some places have been
converted to the use of us_atof() which is locale-independent; fix
all the remaining ones too.