As per
http://package21.nyi.freebsd.org/data/91amd64-default-qat/371223/logs/errors/linux-c6-gtk2-2.20.1.log
there are a few PORTDOCS orphaned. Add them.
x11-toolkits/linux-c6-gtk2: fix plist issues
- Add several PORTDOCS to pkg-plist.
- Deprecate @dirrm{,try} in favor of @dir.
Submitted by: antoine
Approved by: swills (mentor)