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 ncurses-5.9.orig/ncurses/base/MKlib_gen.sh ncurses-5.9/ncurses/base/MKlib_gen.sh
--- ncurses-5.9.orig/ncurses/base/MKlib_gen.sh	2015-09-11 08:07:30.154205355 -0400
+++ ncurses-5.9/ncurses/base/MKlib_gen.sh	2015-09-11 08:10:59.265578376 -0400
@@ -436,12 +436,18 @@
 	-e 's/^\([a-zA-Z_][a-zA-Z_]*[ *]*\)/\1 gen_/' \
 	-e 's/gen_$//' \
 	-e 's/  / /g' >>$TMP
+cat >$ED1 <<EOF
+s/  / /g
+s/^ //
+s/ $//
+s/P_NCURSES_BOOL/NCURSES_BOOL/g
+EOF
+
+sed -e 's/bool/P_NCURSES_BOOL/g' $TMP > $ED2
+cat $ED2 >$TMP
 
 $preprocessor $TMP 2>/dev/null \
-| sed \
-	-e 's/  / /g' \
-	-e 's/^ //' \
-	-e 's/_Bool/NCURSES_BOOL/g' \
+| sed -f $ED1 \
 | $AWK -f $AW2 \
 | sed -f $ED3 \
 | sed \