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             := of-video
$(PKG)_IGNORE   :=
$(PKG)_VERSION  := 2.0.0
$(PKG)_CHECKSUM := f3d2ec3dafd3ab0d0b1215ca7fb391ebd8ebd544
$(PKG)_REMOTE_SUBDIR := 
$(PKG)_SUBDIR   := video-$($(PKG)_VERSION)
$(PKG)_FILE     := $($(PKG)_SUBDIR).tar.gz
$(PKG)_URL      := '$(OCTAVE_FORGE_BASE_URL)/$($(PKG)_FILE)/download'
$(PKG)_DEPS     := ffmpeg

ifeq ($(ENABLE_BINARY_PACKAGES),yes)
    $(PKG)_DEPS += $(OCTAVE_TARGET)
endif

ifeq ($(MXE_SYSTEM),mingw)
$(PKG)_OPTIONS := ac_cv_func_realloc_0_nonnull=yes ac_cv_func_malloc_0_nonnull=yes
else
$(PKG)_OPTIONS := 
endif

define $(PKG)_UPDATE
    $(OCTAVE_FORGE_PKG_UPDATE)
endef

define $(PKG)_BUILD
    $(call OCTAVE_FORGE_PKG_BUILD,$(1),$(2),$(3),$($(PKG)_OPTIONS))
endef