the kernel by wrapping all targets for fake opt_*.h files in
.if defined(KERNBUILDDIR). Thus, such fake files won't be
created at all if modules are built with the kernel.
Some modules undergo cleanup like removing unused or unneeded
options or .h files, without which they wouldn't build this way
or the other.
Reviewed by: ru
Tested by: no binary changes in modules built alone
Tested on: i386 sparc64 amd64
o Add sys/dev/kbdmux/kbdmux.c to the source tree
o Add sys/modules/kbdmux/Makefile to the source tree
These are not yet connected to the build. Man page and other changes to follow.
MFC after: 1 week
