mkswap: remove some dead code
Makefile: add -Wall to default CFLAGS
man: fix warnings
mkswap: fix warnings
su: fix warnings (gcc is wrong)
add loadkmap and dumpkmap

they work the same as those used by busybox, but use a different
magic to differentiate themselves, and are host-endian independent.
so kmap generated with those tools should be portable (at least for
machines that share the same keyboard types).
loadkmap: do not print warning when ioctl fails
add bdiff, a tool to list differences in binaries