Use GTK_WINDOW_POPUP for calendar in clock gadget
Use GTK_WINDOW_POPUP for calendar in clock gadget

Using a popup window saves us from having to set the window manager hints
so less code is needed to show it. We have to have care of not positioning
it over the panel, though.

aperezdc/ggtraybar,aperezdc/ggtraybar,aperezdc/ggtraybar