New build system

[Alan DeKok]

  After a few days of banging on it, it seems to work.  I've just
committed a few changes to address the last few problems.

  A "make -j 8" now works, with the new boilermake.  All dependencies
are tracked.  Some of the dependencies aren't perfect, but they work.

  If there are no cries of pain, we'll spend the next few days deleting
the old build system.

  Alan DeKok.