Instead of continuing to struggle with all the places in arvo where we
assume that vane names are one letter and that one letter is the first
letter of the full vane name, just use %l/lient and %r/rver for now to
finish the split of %light into a separate http client and server vane.
This also fixes up the changes in the vane interface. We can make
a pill with this and can boot it. We can even start the %server app
and ship down a single timer event to the browser, but subsequent
events have broken in the interim; debug on Monday.
