This is the input processing, which starts at rnews (aka cunbatch).  It
invokes newsspool, which actually puts the stuff where it belongs (peeling
off the silly and unnecessary "#! cunbatch" header, if any, as it goes).

Newsrun should be run regularly; it unspools the stuff and feeds it into
the relay subsystem for processing.  Newsrunning can be used to turn this
function on and off if you want to avoid news processing during busy hours.
There is a configuration option to arrange for newsrun to be run after
each newsspool -- this is expensive but cuts down latency.

"make r" builds everything and runs a full regression test on most everything.
