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 libgd-2.1.0-orig/src/Makefile.am libgd-2.1.0/src/Makefile.am
--- libgd-2.1.0-orig/src/Makefile.am	2013-06-25 05:58:23 -0400
+++ libgd-2.1.0/src/Makefile.am	2013-07-14 16:16:20 -0400
@@ -50,7 +50,7 @@
                    gd_tga.c gd_tga.h gd_bmp.c bmp.h gd_color.h gd_nnquant.h gd_tga.h gd_intern.h gd_io_stream.h gd_xbm.c \
 		   gd_color_match.c
 
-libgd_la_LDFLAGS = -version-info $(GDLIB_CURRENT):$(GDLIB_REVISION):$(GDLIB_AGE) -no-undefined
+libgd_la_LDFLAGS = -version-info $(GDLIB_CURRENT):$(GDLIB_REVISION):$(GDLIB_AGE) -no-undefined -export-symbols-regex "xXx"
 
 libgd_la_LIBADD = $(LTLIBICONV)