change the ctdb command table to allow us to describe commands which can be run indep...

change the ctdb command table to allow us to describe commands which can be run independtly of the ctdb daemon.

create a new debugging command xpnn which discovers the pnn of the local node and which works even if the local daemon is not running

(This used to be ctdb commit cd78765f9400d7abce7929a2dd199f65226e7664)