RFC: USES=kernsrc

[René Ladan]

Hi all,

while stagifying the sysutils/biosfont port together with bapt@ at
last EuroBSDCon the idea for a USES=kernsrc (or USES=kld ?) came up.
This new USES would both simplify and unify writing kernel module
ports because it adds all the common lines.

The result is at http://people.freebsd.org/~rene/patches/kernsrc.mk
(download it into Mk/uses/ ). An example of a converted port is at
http://people.freebsd.org/~rene/patches/biosfont.diff

Last nits to solve:
- decide about MAINTAINER
- maybe change plist substitution to "${KMODDIR:C,^/,,}" (i.e. strip
leading '/' )
- maybe mute ${ECHO_CMD} lines (prefix with '@') in kernsrc-post-install target

Documentation:
- add a note to CHANGES
- add a section to the Porters Handbook

Regards,
René