Add initial documentation.

        * doc/Makefile.am: Add mageec.texi for documentation.
        * doc/Makefile.in: Generated.
        * doc/fdl-1.3.texi: Add GFDL 1.3.
        * doc/mdate-sh, doc/texinfo.texi: Add build infrastructure.
        * doc/mageec.texi: Add initial documentation.
        * .gitignore: Ignore .log files.
        * Makefile.am: Build in doc subdirectory.
        * Makefile.in: Rengerated.
        * configure.ac: Generate doc/Makefile.
        * configure: Regenerated.