dist-docs: New utility to generate a documentation bundle for the website.

dist-docs: New utility to generate a documentation bundle for the website.

This utility isn't going to be as portable as most of the Open vSwitch
utilities, unfortunately.  I'm happy to take improvements to make it
able to work with, e.g., the "man" program from BSD.  (I haven't tested
with that program, but I suspect that it is somewhat different from the
GNU version.)

The output of this program can already be viewed at:
	http://openvswitch.org/support/dist-docs/

Signed-off-by: Ben Pfaff <blp@nicira.com>
Acked-by: Thomas Graf <tgraf@noironetworks.com>