get_wwindow_image_from_wmhints scale image
The function get_wwindow_image_from_wmhints returns a image from WM Hints,
but the image could be larger than the desired.
Then, the image can be resized using wIconValidateIconSize(). The resize
should be done in get_rimage_icon_from_wm_hints(), not in the function
get_wwindow_image_from_wmhints(). This is because the function
get_wwindow_image_from_wmhints() is used in wIconStore() too. If we resize
the image before save it to disk, then if we change the icon/dock size, then
the image saved will have a different size than the curren icon size. Is
better resize the image when is painted in the screen, not the image saved.