int: implement own byte swapping functions
int: implement own byte swapping functions

Instead of relying on a non-POSIX header file for such basic functionality,
define our own byte swapping functions.

Signed-off-by: Josef 'Jeff' Sipek <a620f141433c70aa9e43778305a6c68cbfadfb25@josefsipek.net>

jeffpc/libjeffpc,jeffpc/libjeffpc,jeffpc/libjeffpc,jeffpc/libjeffpc