End-to-end verbosity v3

Here's yet another take on the precice verbosity control, this time with -D 2 replacing -v. Everywhere, not just in CLD. Uniformity! BTW, someone forgot to update all the examples when -D with an argument was introduced, so this patch does it now.

These patches have an API change, so as usual CLD must be built first. But surely this ought to be the last logging API change ever, right?

Most importantly, this thing is DEAD:

	/* nsess->udp->sess->log.verbose = 1; */

For some reason it peeved me a lot.

-- Pete