[PD] pdp v4l/pwc fix

[doelie at zzz.kotnet.org]

i've added the workaround for the pwc agc/prefs bug from
pf to pdep. you can update from darcs at

http://zwizwa.goto10.org/darcs/pdp-12

or get the snapshot at

http://zwizwa.goto10.org/darcs/pdp-12/tgz/pdp-0.12.5-test-5.tar.gz

since nobody seems to complain, this will probably be renamed to
official 0.12.5