src/w32fns.c (w32_fullscreen_rect): New function to compute the
window rectangle for the given fullscreen mode.
(w32_wnd_proc): When in a fullscreen mode, WM_WINDOWPOSCHANGING no
longer tunes the window size. This keeps the window's edges flush
with the screen and allows the taskbar to hide itself in fullboth.
src/w32term.c (w32fullscreen_hook): 'fullboth' now shows without
window decorations and uses the entire screen.
src/w32term.h (w32_fullscreen_rect) Add prototype.
(struct w32_output): Replace normal_width, normal_height,
normal_top, and normal_left members with a single normal_placement
struct.
(FRAME_NORMAL_WIDTH, FRAME_NORMAL_HEIGHT, FRAME_NORMAL_TOP):
Remove macros.
(FRAME_NORMAL_PLACEMENT): New macro.