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.

PKG             := uuid
$(PKG)_IGNORE   = $(mingw-w64_IGNORE)
$(PKG)_VERSION  = 3.17
$(PKG)_CHECKSUM = $(mingw-w64_CHECKSUM)
$(PKG)_SUBDIR   = $(mingw-w64_SUBDIR)
$(PKG)_FILE     = $(mingw-w64_FILE)
$(PKG)_URL      = $(mingw-w64_URL)
$(PKG)_DEPS     = mingw-w64

define $(PKG)_UPDATE
    echo "$($(PKG)_VERSION)"
endef

define $(PKG)_BUILD
    if [ $(BUILD_SHARED) = yes ]; then \
      $(INSTALL) -d '$(HOST_BINDIR)'; \
      $(MAKE_SHARED_FROM_STATIC) --ar '$(MXE_AR)' --ld '$(MXE_CC)' '$(HOST_LIBDIR)/libuuid.a' --install '$(INSTALL)' --libdir '$(HOST_LIBDIR)' --bindir '$(HOST_BINDIR)'; \
      rm -f $(HOST_LIBDIR)/libuuid.dll.a; \
    fi
endef