* fix segv in parameter parsing

	sudo cowbuilder -M aaa bbb cccc

* cowbuilder should support configuration files for some configs.

* signal handling; do I support ctrl-C reasonably? (no)

* .ilist file position

  I think the bottleneck is now in .ilist file re-generation, on
   multiple invocations of cowdancer; can I consolidate it in
   cowbuilder?
  Operationally, a file in ./.ilist is inconvenient.
  If I put it in /tmp, I need to delete it, or a tmpreaper is
   required; and the file isn't too small.

* hardlink behavior.

If I had a hardlinked file, I would expect both files to be updated 
at the same time. Currently, it will only update one of the files.

mkdir 1
touch 1/a
ln 1/a 1/b
cp -al 1 2
cowdancer

echo test > 2/b

will result in 2/b being different to 2/a.

This has implications, and I think this should be documented.

* Investigate fchmod/fchown
It is partially implemented, but difficult to really do.
open(, RDONLY) and fchmod/fchown is hard to do, because we're handling
inodes at that timing.

