Bug#505213: x11vnc depends on the tk8.4 package

["Karl J. Runge" <runge@karlrunge.com>]

Package: x11vnc
Version: 0.9.3.dfsg.1-1

The x11vnc program's "-gui" option depends on the tk8.4 package (via
/usr/bin/wish).  Linux distros like debian seem to not ship this utility
by default as they once did.

The x11vnc gui mode is optional and doesn't look terribly nice, but by
having tk/wish installed it would work by default and would enable a
some useful things.

One thing it would enable is creating a desktop menu item that would
launch a gui for x11vnc.  E.g. 'x11vnc -gui tray=setpass -rfbport 5900'
intended for naive users.  This would enable addressing bug #475113:

	http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=475113