Reimplement the multi-dimensional arrays that are used to set up the

Reimplement the multi-dimensional arrays that are used to set up the
process to process imsg communication.  It became a maze after we
added support for multiple relay processes and even worse with the ca
processes.  This change makes it easier to understand.  Now it only
opens socketpairs that are needed - the code previously wasted lots of
fds.

ok blambert@