Introduce panel window list and surface minimize protocol

[Scott Moreau]

This series implements a window list for the panel. It introduces protocol for
minimize/maximize control of shell_surfaces. It also provides a basic
minimize implementation.

Admittedly I am a little confused about the interface version system. I am
wondering if we should have something such as a changlog file kept in the
protocol folder.

Aside from this, the window list seems to work pretty well with all the new
functionality that it offers. Minimized buttons are hooked up by this series
as well, which means we can start fleshing out the decorations in other clients
and toolkits. The list operation is dynamic, supporting multiple outputs.

Changed in v3:

- Rebased to latest master
- Addressed everything listed here:
	http://lists.freedesktop.org/archives/wayland-devel/2012-November/006485.html
- Additional bug fixes


Here is a breif video clip demoing the latest code:

http://www.youtube.com/watch?v=nv5isdcxBcY