wined3d: At the start of RemoveContextFromArray numContexts is decreased by 1, the loop which loops through the whole array doesn't take this into account.

Discovered by Peter Oberndorfer.

winex11.drv: Rename X11DRV_DIB_BitmapInfoSize to bitmap_info_size and fix to take into account bit field masks.

As Wine ignores SIGCHLD, waitpid() works on Linux only by accident. On
FreeBSD it doesn't work.