XEmbed systray patch bugs

[James Liggett]

Hi Mike and Rob,
I tried your patch for XEmbed systray support, and I'm pretty impressed
with it. I think it's about time someone finally dusted this one off and
tried to get it committed. But, I've noticed some issues:

1. The "Wine-Systray" window is still showing up. I've been able to fix
this by getting rid of the WS_VISIBLE style when creating the window in
systray.c, and then manually showing the window after it's been docked. 
2. The rightmost edges of systray icons are cut off. The previous fix
seemed to work for this problem too. I think it has something to do with
painting/updating the embedded window.
3. Sometimes, systray icons don't show up at all. I notice this when
exiting a program that uses systray and then starting it again. On the
second consecutive run, the icon doesn't show up at all. It must be some
kind of window-management problem, because I still see the Wine-systray
window after after the program I'm using exits. I can only make it go
away after restarting my window manager (Metacity with the GNOME
desktop) Looks like some kind of cleanup issue. I'm working on this one.

For reference, the two programs I've been using for testing are Palm
Hotsync and Steam. When I get some more free time, I'll put together a
simpler test case to nail down that third problem. All that aside, good
work guys! :)

James