Some (probably) easy uwp patches
commit 990e013c:
gutils: Remove dead code used for Windows SDK versions
We require a newer SDK version now, so this is not needed.
commit f4fa8ca1:
windows: Move G_WINAPI_ONLY_APP to config.h
Also convert it from a define to 1 || 0
commit ccc3d377:
gmodule: Don't try to use toolhelp for symbol searching on UWP
This is not allowed under UWP.
commit 71f11710:
glib: Don't call MessageBox() when building for UWP
However, it's fine to call it when building for the debug target
(which uses the debug CRT and hence sets -D_DEBUG), so let's keep that
around.
The Windows App Certification Kit only runs on apps built in release
mode.
Edited by Nirbheek Chauhan