r11909: Implement 'reset on zero vc'. This kills other connections when a session

r11909: Implement 'reset on zero vc'. This kills other connections when a session
setup comes in with the vc (virtual connection) field set to zero. This is
done by Windows, probably you can tweak that by some registry key.

	This boolean option controls whether an incoming session setup
	should kill other connections coming from the same IP. This matches
        the default Windows 2003 behaviour.

	Setting this parameter to yes becomes necessary when you have a flaky
	network and windows decides to reconnect while the old connection
	still has files with share modes open. These files become inaccessible
	over the new connection.

	The client sends a zero VC on the new connection, and Windows 2003
	kills all other connections coming from the same IP. This way the
	locked files are accessible again.

	Please be aware that enabling this option will kill connections behind
	a masquerading router.

Volker
(This used to be commit 5629ca16235f0aa21fea3afd9e414309e4e1374e)