Update libpng from 1.6.3 to 1.6.10

Change-Id: I76e81e7fd267d15991cd342c5caeb2fe77964ebf
diff --git a/scripts/makefile.openbsd b/scripts/makefile.openbsd
index 421a266..c61fa2e 100644
--- a/scripts/makefile.openbsd
+++ b/scripts/makefile.openbsd
@@ -1,6 +1,6 @@
 # makefile for libpng
+# Copyright (C) 2007-2009, 2014 Glenn Randers-Pehrson
 # Copyright (C) 1995 Guy Eric Schalnat, Group 42, Inc.
-# Copyright (C) 2007-2009 Glenn Randers-Pehrson
 #
 # This code is released under the libpng license.
 # For conditions of distribution and use, see the disclaimer
@@ -11,7 +11,7 @@
 MANDIR= ${PREFIX}/man/cat
 
 SHLIB_MAJOR=	16
-SHLIB_MINOR=	1.6.3
+SHLIB_MINOR=	1.6.10
 
 LIB=	png
 SRCS=	png.c pngerror.c pngget.c pngmem.c pngpread.c \
@@ -28,8 +28,11 @@
 CLEANFILES+= pngtest.o pngtest pnglibconf.h
 
 MAN=	libpng.3 libpngpf.3 png.5
-DOCS = ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO \
-       libpng-manual.txt
+DOCS=	ANNOUNCE CHANGES INSTALL KNOWNBUG LICENSE README TODO Y2KINFO \
+	libpng-manual.txt
+
+.c.o:
+	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $<
 
 # see scripts/pnglibconf.mak for more options
 pnglibconf.h: scripts/pnglibconf.h.prebuilt