Add build rule for build-octave (bug #49503). * src/build-octave.mk: Add new build rule for build-octave which can be used for cross-building binary packages that depend on Octave as a build tool. * dist-files.mk: Add new file to list. * index.html: Add new package to list. * src/of-communications.mk, src/of-image.mk, src/of-mapping.mk, src/of-optiminterp.mk, src/of-sparsersb.mk, src/of-statistics.mk, src/of-windows.mk: Add optional dependency on build-octave. * configure.ac: Add new configure switch "--disable-system-octave" that is needed to build the build-octave package. * Makefile.in: Add variable "USE_SYSTEM_OCTAVE". Exclude build-octave from the default build tools and build it only if a package explicitly depends on it. Display warning about missing native Octave version only if necessary.

#! /bin/sh

## Run from top-level mxe-octave directory.

set -e

top_dir=`pwd`

make_ver="4.1"
make_dir="make-$make_ver"
make_pkg="$make_dir.tar.gz"

if [ ! -d pkg ]; then
  mkdir pkg
fi

if [ ! -f pkg/$make_pkg ]; then
  wget ftp://ftp.gnu.org/gnu/make/$make_pkg -O pkg/$make_pkg
fi

rm -rf $make_dir

tar zxf pkg/$make_pkg

cd $make_dir

./configure --prefix=$top_dir/usr

make

make install

cd $top_dir

rm -rf $make_dir