Migrate the rest of tests/ to GPLv3. - drag 'n drop was also done by Oliver Graf, so samy copyright - with gtk-test.glade, the only question was where to actually stick the attribution; inserted XML comment

#!/bin/sh
if
test -r $2
then
if
cmp $1 $2 > /dev/null
then
echo $2 is unchanged
rm -f $1
else
mv -f $1 $2
fi
else
mv -f $1 $2
fi