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 pixman-0.30.0-orig/pixman/Makefile.in pixman-0.30.0/pixman/Makefile.in
--- pixman-0.30.0-orig/pixman/Makefile.in	2013-05-08 19:25:31 -0400
+++ pixman-0.30.0/pixman/Makefile.in	2013-07-22 12:07:31 -0400
@@ -475,7 +475,7 @@
 lib_LTLIBRARIES = libpixman-1.la
 libpixman_1_la_LDFLAGS = -version-info $(LT_VERSION_INFO) \
 	-no-undefined @PTHREAD_LDFLAGS@ $(am__append_2) \
-	$(am__append_7) $(am__append_18)
+	$(am__append_7) $(am__append_18) -export-symbols-regex "^pixman_.*"
 libpixman_1_la_LIBADD = @PTHREAD_LIBS@ -lm $(am__append_3) \
 	$(am__append_5) $(am__append_8) $(am__append_10) \
 	$(am__append_12) $(am__append_14) $(am__append_16) \