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.

/*
 * This file is part of MXE.
 * See index.html for further information.
 */

#include <json/json.h>
#include <stdio.h> 

int main(int argc, char *argv[])
{
    json_object *jobj;

    (void)argc;
    (void)argv;

    jobj = json_object_new_object();
    if (!jobj) {
        return 1;
    }
    json_object_object_add(jobj, "key", json_object_new_string("value"));
    printf("%s", json_object_to_json_string(jobj));
    return 0;
}