Started handling errors in the Windows Popover code. Also more TODOs.
More Windows popover error checking.
Switched to using Polyline() in the Windows Popover code.
Genericized the popover code to allow pointing in any direction and at any point. This only affects the shaping; everything else needs to be done now.
More Windows popover error checking and bug fixes.
Fixed up the Windows Popover so that it can point in any direction and the client area adjusts itself properly.
Started the replacement GTK+ Popover.