First pass at removing calls to fork from the shared port daemon.  #4094

Instead of having the shared port fork, the idea is to use non-blocking
I/O by simply registering the socket for a response from daemonCore
in the parent process.
Mark socket as non-blocking when a connection attempt is made. #4094

This causes clients to be rejected as soon as the daemon's backlog
is hit.  This is equivalent behavior to the case where the daemon
is listening on the network and the TCP socket backlogs.
ifdef out portions which will not compile under Windows. #4094
Only fixes to whitespace (tab stop is 4, not 8), add comments. #4094