I just pushed the first example of a configure script

[Fredrik Öhrström]

As you will quickly notice, the resulting source code now does not compile.
:-)
This update was needed just to show the basic principles behind
the intended use of configure. I.e. we use only autoconf to generate
a configure script. We do not use any of the other auto tools.

When the configure script is run, a spec.gmk file is created
where all settings are localized. Thus we want to move away
from configuring the build using env variables.

The configure script has a standardized api for help and
settings and cross compilation support that is familiar
to many. The configure script will do lookups
for tools and sanity checks, that were previously
spread out in different Makefiles.

The configure script can give the programmer assistance
when looking for tools, and even give context sensitive help on
how to acquire needed libraries.

There is also support for configuring a standardized set
of build dependencies that are automatically downloaded
and used for the build. An example of such a conf file
is located in common/config/builddeps.conf.example
This is a feature that we will use in-house, but you are
welcome to use it too, but you will have to setup your own
builddeps servers.

To make it actually compile, is left as a reader exercise!
Or you can just wait for the next commit....

//Fredrik

PS: Unless you are running from an x86_64-unknown-linux-gnu system,
you will need to install config.guess and config.sub from the autoconf
package into common/config. To rebuild the configure script you also
need pkg.m4 from pkg-config. These files will be added for real
to the repositories as soon as the paperwork is done here.