Add Ripley` to AUTHORS
Fix build of Debian package

The build of the Debian package had the following issues:
* AUTHORS, CHANGELOG and COPYRIGHT files were placed in /usr/lib/openra
* /usr/share/doc/openra/changelog.gz did not contain the changelog
Merge pull request #4473 from chrisforbes/authors

Add Ripley` to AUTHORS
More cleanups, leave AUTHORS file in the libdir
Merge pull request #4481 from obrakmann/linux-packaging

Fix build of Debian package