A known issue with gdmdynamic is that when a display connects to
        the server it generates the gdmdynamic "ADD" and "RELEASE" commands.
        On startup, hundreds of displays could send these commands at once
        and cause the server too be flooded with sockets requests.  Hammering
        the socket like this caused me to find and fix a number of problems
        that improve socket reliability for general GDM use.  I also enhanced
        gdmdynamic so it is more sensitive to the socket being busy and no
        longer overloads it, instead sleeping and retrying if necessary.  This
        allows gdmdynamic to work if there are hundreds of displays instead of
        just a dozen or so.

        * daemon/gdm.[ch]: Added new "SERVER_BUSY" sockets command so that
          gdmdynamic can sleep before starting new slaves if the daemon is
          already busy.
        * daemon/gdm-net.[ch]: Bump up MAX_CONNECTIONS fr...