src/Tools/Metis/fix_metis_license

updated to sumatra_pdf-3.1.2-1: x86_64-windows;

#!/usr/bin/env bash
THIS=$(cd "$(dirname "$0")"; echo $PWD)
(cd $THIS;
 perl -p -i~ -w -e 's/MIT license/BSD License/g' Makefile src/*.s* scripts/mlpp)