VNC First connection patch

This patch modifies the behaviour of the UNIX VNC server so that a connection will not be disconnected if another user tries to establish the connection.

This allows Xvnc to be included in your Xservers file without password protection, and allowing XDM to authenticate users instead.

This patch is only useful if you aren't using VNC-level passwords, and have some other form of security (such as a login account in the case of XDM.)

Requirements:

1. Should patch cleanly on both r1 and r2 of the unix VNC source distribution.

Summary: