Abandon the `m4'-based build system. And there was great rejoicing.

The makefile has been entirely rewritten using old-fashioned Automake.
I've used the undocumented `foo_OBJECTS' variables in a couple of places
to make parallel builds work, but those will disappear again in the
course of future rearrangements of the source tree.

A couple of the scungier programs for building boilerplate source files
have been replaced by the marvellous new template-substitution program
`multigen'.

The `qcc' script is a casualty of the rearrangements.  Supporting it is
easy, but probably pointless.  So it's gone.

Currently most of the generated code is left in the build tree (rather
than the source tree) and not distributed.  This wants to be fixed
later, but the exact machinery will be rather different.

This is only the start of a programme of overhauling Catacomb's ageing
and rather nasty build system.  The objective is to end up with modern-
looking build scripts, and a pleasant and sensible directory tree.  Not
much of the actual code will change during this, though lots of it will
move around.  In particular, the testing machinery is likely to be
overhauled quite a lot.