[libpng16] Update internal version numbering and SO-numbers

scripts/makefile.darwin

@@ -9,7 +9,7 @@
 # For conditions of distribution and use, see the disclaimer
 # and license in png.h
 
-# where "make install" puts libpng.a, libpng15.dylib, png.h, pngconf.h,
+# where "make install" puts libpng.a, libpng16.dylib, png.h, pngconf.h,
 # and pnglibconf.h
 prefix=/usr/local
 exec_prefix=$(prefix)
@@ -21,8 +21,8 @@ ZLIBLIB=../zlib
 ZLIBINC=../zlib
 
 # Library name:
-LIBNAME = libpng15
-PNGMAJ = 15
+LIBNAME = libpng16
+PNGMAJ = 16
 
 # Shared library names:
 LIBSO=$(LIBNAME).dylib
@@ -41,7 +41,7 @@ ARCH="-arch i386 -arch x86_64"
 
 # CFLAGS=-I$(ZLIBINC) -W -Wall -O3 -funroll-loops
 CFLAGS=-I$(ZLIBINC) -W -Wall -O -funroll-loops $(ARCH)
-LDFLAGS=-L. -L$(ZLIBLIB) -lpng15 -lz $(ARCH)
+LDFLAGS=-L. -L$(ZLIBLIB) -lpng16 -lz $(ARCH)
 
 INCPATH=$(prefix)/include
 LIBPATH=$(exec_prefix)/lib
@@ -89,14 +89,14 @@ libpng.pc:
 	-e s!@exec_prefix@!$(exec_prefix)! \
 	-e s!@libdir@!$(LIBPATH)! \
 	-e s!@includedir@!$(INCPATH)! \
-	-e s!-lpng15!-lpng15\ -lz! > libpng.pc
+	-e s!-lpng16!-lpng16\ -lz! > libpng.pc
 
 libpng-config:
 	( cat scripts/libpng-config-head.in; \
 	echo prefix=\"$(prefix)\"; \
 	echo I_opts=\"-I$(INCPATH)/$(LIBNAME)\"; \
 	echo L_opts=\"-L$(LIBPATH)\"; \
-	echo libs=\"-lpng15 -lz\"; \
+	echo libs=\"-lpng16 -lz\"; \
 	cat scripts/libpng-config-body.in ) > libpng-config
 	chmod +x libpng-config
 
@@ -106,7 +106,7 @@ $(LIBSO): $(LIBSOMAJ)
 $(LIBSOMAJ): $(OBJSDLL)
 	$(CC) -dynamiclib \
 	 -install_name $(LIBPATH)/$(LIBSOMAJ) \
-	 -current_version 15 -compatibility_version 15 \
+	 -current_version 16 -compatibility_version 16 \
 	 -o $(LIBSOMAJ) \
 	 $(OBJSDLL) -L$(ZLIBLIB) -lz