window: Set a minimum size for toytoolkit windows
window: Set a minimum size for toytoolkit windows

The decorations tiles start to overlap and look weird if we go below
200x200 size windows.  Just set that as a minimum size if the app
doesn't provide a bigger minimum size.

https://bugs.freedesktop.org/show_bug.cgi?id=66794

Fantu/compositor-spice,udoprog/weston,Fantu/compositor-spice,kwm81/weston,sir-murray/weston,Gnurou/weston,Fantu/compositor-spice,sir-murray/weston,xorgy/weston,mchalupa/weston,udoprog/weston,Tarnyko/weston-xdg_surface_present,giucam/weston,eyolfson/weston,Gnurou/weston,krezovic/weston,Tarnyko/weston-xdg_surface_present,eyolfson/weston,krezovic/weston,jonnylamb/weston,jonnylamb/weston,giucam/weston,kwm81/weston,xorgy/weston,mchalupa/weston