9p: update maintainers and documentation

Updates to the MAINTAINERS file and documentation for 9p to point to the
swik wiki versus the outdated sf.net page.  Also updated some email addresses
and added pointers to papers which better describe the implementation and
application of the Linux 9p client.

Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
2 files changed