Add debian build files to enable building of Debian package using for example
debuild -b or dpkg-buildpackage -us -uc
Extend the .gitignore.
The debhelper checks show warnings and errors that will need to be addressed
some other time. For some I don't know how to solve them at the moment.
Signed-off-by: Stefan Berger <stefanb@linux.watson.ibm.com>