Configuration and build clean-up

As an on-going process starting now I would like to begin cleaning up the
configuration and build process, in particular to eventually have

* Separate build directory

* Automatic dependency tracking

* Semi-automatic packaging

as well as to

* Remove a number of hacks, bogosities, and faults

* Be ready for the next Autoconf release, coming soon

but most of all to

* Make life easier for users and developers

Changes will mostly be internal but to get most of this to work okay the
configure script really needs to live in the top level directory of the
package.

Rationale:

- This is where users expect it and everyone else has it.

- Separate build directories will behave more sensical.

- Would be nice if a top level makefile took care of the documentation
build and install as well.

- Automated packaging will really not work otherwise.

In order to not clutter the top level directory with stuff such as
`config.guess', I suggest making a separate directory `config/' where to
put all these things (incl. install-sh, mkinstalldirs, etc.), as there
will probably be more as we go along.

This layout is recommended by the Autoconf maintainers, btw.

Any objections to this point?

--
Peter Eisentraut Sernanders väg 10:115
peter_e(at)gmx(dot)net 75262 Uppsala
http://yi.org/peter-e/ Sweden