Code of Conduct: Let's revamp it.

The Code of Conflict is not achieving its implicit goal of fostering
civility and the spirit of 'be excellent to each other'.  Explicit
guidelines have demonstrated success in other projects and other areas
of the kernel.

Here is a Code of Conduct statement for the wider kernel.  It is based
on the Contributor Covenant as described at www.contributor-covenant.org

From this point forward, we should abide by these rules in order to help
make the kernel community a welcoming environment to participate in.

Signed-off-by: Chris Mason <clm@fb.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Olof Johansson <olof@lxom.net>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>