Add autoconf CIG m4 macros
Added m4 submodule
Added archimedes python module manually.

In the SVN repository archimedes was an external repository. Since it is just a single file and hasn't changed in several years and it is likely to go away, the file was added manually rather than using a submodule.
Added .gitignore.

Developers will want to add patterns like *.pyc to their global ignore rules.
Added other autoconf repo references