cure -pedantic warnings (c++ comments) to prepare for removing a bunch of cflags
remove most of the platform specific defines/compiler flags:
remove all of _POSIX_C_SOURCE, _BSD_SOURCE, _XOPEN_SOURCE,
and also -std=gnu99|c99 flags.  remove -U__STRICT_ANSI__
which is not necessary anymore.  add a local copy of strdup
as wm_strdup, so that we do not rely on platform-specific
defines to get its prototype. rearrange includes in player
app, so that termios.h is included the last, and do define
_XOPEN_SOURCE as 600 just before including it so that ONLCR
is available to us.
defining _XOPEN_SOURCE as 600 for ONLCR after including other
system headers needn't work at all. therefore confine the tty
stuff in a new compilation unit.
defining _XOPEN_SOURCE as 600 for ONLCR after including other
system headers needn't work at all. therefore confine the tty
stuff in a new compilation unit.
player: no need for strdup at all, local or otherwise: static arrays work perfectly for pcmname and config_file
use a local inline isdigit implementation.