Add patches for building packages with UCRT. * src/flac-1-ucrt.patch, src/gdal-2-ucrt.patch, src/mesa-2-ucrt.patch: Don't set specific msvcrt version. * src/flac.mk: autoreconf after applying patch. * dist-files.mk: Add new files to build system.

#!/bin/bash
## bootstrap script
## Run this to generate the configure script

set -e      # halt if unhandled error
aclocal
autoconf    # generate configure script