Avoid runtime dependencies to e.g. libpwinthread-1.dll, libstc++-6.dll.
This prevents Qt Creator from spitting out error dialogs on each startup
for registered MinGW versions that aren't in the default PATH.
Change-Id: Id55518db8c8e0521b6a41add1eaf38f75a892c8b
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>