This patch adds GUI::DisplayLink, a mechanism for registering callbacks
that will fire at the display refresh rate.
Note that we don't actually know the screen refresh rate, but this is
instead completely driven by WindowServer's compositing timer. For all
current intents and purposes it does the job well enough. :^)
Previously it was only possible to change these window attributes when
creating a new window. This patch adds an IPC message that allows you
to change them at runtime.
We were not repainting windows that were occluded at the time of the
theme changing. This patch adds a way to bypass occlusion testing when
invalidating window rects.
Fixes#1249.
This patch removes the internal system menu from WindowServer and
replaces it with two IPC API's:
SetSystemMenu(menu_id)
SetSystemTheme(theme_path, theme_name)
These API's will allow us to complete the SystemMenu program and
move it entirely out of process.
