(io_select, io_init, io_open, io_close, io_output, io_flush, io_write,

io_puts, iom_create, iom_getmask, iom_set, iom_clear, iom_zero):
Portability bug: io_select() passed bit_fdmask to select().  This
breaks the fd_set abstraction, and works only with the traditional
Unix implementation of fd_set.  Use fd_set and its operations instead.
Remove unused source files.  Note: the offending code is currently
unsued.  But it's a time bomb, and fixing it also replaces a bunch of
code by standard library services.

src/lib/player/accept.c

@@ -33,7 +33,6 @@
 
 #include "prototypes.h"
 #include "misc.h"
-#include "bit.h"
 #include "proto.h"
 #include "empthread.h"
 #include "player.h"