Added some file for building with autotools.

Signed-off-by: Bert Timmerman <bert.timmerman@xs4all.nl>
A README file is required.

Signed-off-by: Bert Timmerman <bert.timmerman@xs4all.nl>
Added a ChangeLog.

Signed-off-by: Bert Timmerman <bert.timmerman@xs4all.nl>
autogen.sh: grep for configure.ac.

Signed-off-by: Bert Timmerman <bert.timmerman@xs4all.nl>
configure.ac: config headers with autoconf macro.

Signed-off-by: Bert Timmerman <bert.timmerman@xs4all.nl>
configure.ac: initialise with warning levels
and foreign to GNU standards.

Signed-off-by: Bert Timmerman <bert.timmerman@xs4all.nl>
Initialising automake with "foreign".

Drop the README link to file README.plug-ins.

Signed-off-by: Bert Timmerman <bert.timmerman@xs4all.nl>