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.

diff -ur a/engines/ccgost/Makefile b/engines/ccgost/Makefile
--- a/engines/ccgost/Makefile	2013-02-11 10:26:04.000000000 -0500
+++ b/engines/ccgost/Makefile	2013-10-14 13:38:18.595806411 -0400
@@ -32,7 +32,7 @@
 		$(MAKE) -f $(TOP)/Makefile.shared -e \
 			LIBNAME=$(LIBNAME) \
 			LIBEXTRAS='$(LIBOBJ)' \
-			LIBDEPS='-L$(TOP) -lcrypto' \
+			LIBDEPS='-L$(TOP) -lcrypto -lgdi32' \
 			link_o.$(SHLIB_TARGET); \
 	else \
 		$(AR) $(LIB) $(LIBOBJ); \