[compiz] Thumbnail plugin

[Stjepan Glavina]

Tommorow I'll make a new version. It will just use patched
libwnck/kdebase as this is the clean way. This way it'll be very
bug-free.
David, do you have any plans to put this plugin into the main compiz GIT
repository? If you do this, I'll add a bug report to GNOME devs and
request the patch to be included in libwnck.

Panel apps (gnome-panel, kicker, xfce4-panel) change the property to
request a thumbnail. The plugin draws it (even with window decorations).
This is the best way of functioning I can think of.
I also made a version which draws thumbnails with no interaction with
the panel. This results in buggy and hacky code.
There's no doubt the first way is better.

If you don't think it's good enough to be in the main repository, tell
me why.

Stjepan