With this patch the window manager related functionality is split out
onto a new endpoint pair named WindowManagerServer/Client. This allows
window manager functionality to be potentially privilege separated in
the future. To this end, a new client named WMConnectionClient
is used to maintain a window manager connection. When a process
connects to the endpoint and greets the WindowServer as a window manager
(via Window::make_window_manager(int)), they're subscribed to the events
they requested via the WM event mask.
This patch also removes the hardcoding of the Taskbar WindowType to
receive WM events automatically. However, being a window manager still
requires having an active window, at the moment.
WindowServer now collects applet windows into an "applet area" which is
really just a window that a WM (window management) client can position
via IPC.
This is rather hackish, and I think we should come up with a better
architecture eventually, but this brings back the missing applets since
the global menu where they used to live is gone.
Window icons in Taskbar were previously received in WM events with
shbuf ID's. Now that Gfx::ShareableBitmap is backed by anonymous files,
we can easily switch to using those.
