win32: properly handle show and focus

win32: properly handle show and focus

The first time a window is shown we should always call SW_SHOWNORMAL.
Understand whether to call SW_SHOW or SW_SHOWNORMAL and the specific
ones for the temporary windows depending on IsWindowVisible.
This also fixes the problem when calling gtk_window_present and
the window is snapped to the left or right of the screen.

This patch is based on the patches provided by Yevgen Muntyan
and Aleksander Morgado.

https://bugzilla.gnome.org/show_bug.cgi?id=698652