Added (*w.window).Option methods to the backends and use them for setting the initial options passed into NewWindow.
Signed-off-by: pierre <pierre.curto@gmail.com>
Package wm (for "window manager") is a better fit for the package, and
distinguishes it from the low-level package windows for the Windows API.
Signed-off-by: Elias Naur <mail@eliasnaur.com>