XXX !!! XXX !!!
I noticed a few semi-serious bugs while doing this merge, one of which
has existed for a fairly long time. Some of them are addressed in this
commit (because they caused the kernel to not compile), and are annoted
by "XXX" and "--thorpej". The other one will be addressed shortly in
a future commit, and, as far as I can tell, affects all operating systems
which IP Filter supports.