Added Add/RemoveWindow methods to Screen.
Started the implementations of Un/ManageWindow methods from WindowManager in X11XCB_WindowManager.
Added GetScreens method to WindowManager.
Attach new clients to the screen of their origin.
Improved const correctness with iterators in X11XCB_WindowManager.
Accept Position and Size in the window constructor.
Call PrimaryWindow::SetScreen from X11XCB_Screen::AddWindow.
Make use of the ManageWindow method.
Document the window manager code a bit.
Delete GeometryReply when we're done with it.
Set the event mask on the root window AFTER properties have been set.
Added a move/resize interface to Window and implemented it.