Updatetool GUI/Notifier IPC protocol.

This protocol facilates basic operations between the GUI and the
notifier.  For example the notifier can trigger a running GUI to
display pending updates or the GUI can trigger a running notifier
to check for new updates.

The clients listen for connections in the private port range: 49152-65535.
If the client sends an invalid command the connection is dropped.

Connections are handled serially.  A new connection will not be
accepted until the current connection closes.

The ports currently in use by the GUI and notifier are maintained
in <App preferences directory>/{ut, nt}_lock-{fully qualified hostname}:

nt_lock-aha.red.iplanet.com  ut_lock-aha.red.iplanet.com

---------

Protocol:

Client					Server              Comments
------------------------------------------------------------------------------

VERSION			--->		                    Not implemented
		        <---		X.Y.Z.A             Issue 616

HELLO			--->						
			<---		OK		

SHOW			--->                                Raise/Restore app.
			<---		OK		

LOAD_CONFIG		--->                                Reload preferences
			<---		OK		

SHOW_UPDATES		--->                                Show/Start UT.  
			<---		OK		

APPLY_UPDATES		--->                                Show Updates/Ask 
			<---		OK		    user if ok to apply.

CHECK_UPDATES		--->                                Notifier: Check for
			<---		OK		    any new updates.

RESTART		        --->                                Restart yourself.
			<---		OK		

GOODBYE	                --->
			<---		OK, <close cxn>

????                    --->
			<---		<close cxn>