Cleanups to RPC code.

This is extracted from a significantly longer RPC change that I put down a couple of weeks ago.

It deletes some unused code, uses Issue and Book a little more, and fixes some long lines and indentation.

Feel free to use this or ignore it!
This is less than a quibble.  I believe that explicit (which was already there) is unnecessary if there are two or more required arguments on a constructor.  Of course the extra explicit hurts nothing.