Removed support of pngprefs.h from makefiles.

It is no longer used since the MMX support was removed.
diff --git a/scripts/makefile.mingw b/scripts/makefile.mingw
index 05e9b87..ffebcbc 100644
--- a/scripts/makefile.mingw
+++ b/scripts/makefile.mingw
@@ -4,7 +4,7 @@
 #   statically linked and one dynamically linked.
 #
 # Built from makefile.cygwin
-# Copyright (C) 2002, 2006 Soren Anderson, Charles Wilson,
+# Copyright (C) 2002, 2006, 2008 Soren Anderson, Charles Wilson,
 #    and Glenn Randers-Pehrson, based on makefile for linux-elf w/mmx by:
 # Copyright (C) 1998-2000, 2007 Greg Roelofs
 # Copyright (C) 1996, 1997 Andreas Dilger
@@ -39,11 +39,6 @@
 
 MKDIR_P=/bin/mkdir -pv
 
-
-# To enable assembler optimizations, add '-DPNG_USE_PNGGCCRD' to
-# $CFLAGS, and include pnggccrd.o in $OBJS, below.
-
-
 # Where "make install" puts libpng*.a, *png*.dll, png.h, and pngconf.h
 ifndef prefix
 prefix=/usr
@@ -63,23 +58,12 @@
 	-Wmissing-declarations -Wtraditional -Wcast-align \
 	-Wstrict-prototypes -Wmissing-prototypes #-Wconversion
 
-### if you use the asm, add pnggccrd.o to the OBJS list
-###
-### if you don't need thread safety, but want the asm accel
-#CFLAGS= $(strip $(MINGW_CCFLAGS) -DPNG_THREAD_UNSAFE_OK -DPNG_USE_PNGGCCRD \
-#	$(addprefix -I,$(ZLIBINC)) -W -Wall -O3 $(ALIGN) -funroll-loops \
-#	-fomit-frame-pointer)  # $(WARNMORE) -g -DPNG_DEBUG=5
-### if you need thread safety and want (minimal) asm accel
-#CFLAGS= $(strip $(MINGW_CCFLAGS) -DPNG_USE_PNGGCCRD $(addprefix -I,$(ZLIBINC)) \
-#	-W -Wall -O3 $(ALIGN) -funroll-loops \
-#	-fomit-frame-pointer)  # $(WARNMORE) -g -DPNG_DEBUG=5
-### Normal (non-asm) compilation
 CFLAGS= $(strip $(MINGW_CCFLAGS) $(addprefix -I,$(ZLIBINC)) \
         -W -Wall -O3 $(ALIGN) -funroll-loops \
 	-fomit-frame-pointer) # $(WARNMORE) -g -DPNG_DEBUG=5
 
 LIBNAME = libpng14
-PNGMAJ = 14 
+PNGMAJ = 14
 MINGDLL = 14
 PNGMIN = 1.4.0beta57
 PNGVER = $(PNGMAJ).$(PNGMIN)
@@ -112,7 +96,7 @@
 
 OBJS = png.o pngset.o pngget.o pngrutil.o pngtrans.o pngwutil.o \
 	pngread.o pngrio.o pngwio.o pngwrite.o pngrtran.o \
-	pngwtran.o pngmem.o pngerror.o pngpread.o # pnggccrd.o
+	pngwtran.o pngmem.o pngerror.o pngpread.o
 
 OBJSDLL = $(OBJS:.o=.pic.o)
 
@@ -124,15 +108,7 @@
 %.pic.o : %.c
 	$(CC) -c $(CFLAGS) -o $@ $<
 
-all: all-static all-shared libpng.pc libpng-config libpng.pc libpng-config \
-	pngdefs.h
-
-pngdefs.h:
-	echo "/* pngdefs.h was built by makefile.mingw */" > pngdefs.h
-	/* if you don't want to use the intel MMX code, uncomment this */
-	# echo "#define PNG_NO_MMX_CODE" >> pngdefs.h
-	/* if you don't need thread safety you can uncomment this */
-	# echo "#define PNG_THREAD_UNSAFE_OK" >> pngdefs.h
+all: all-static all-shared libpng.pc libpng-config libpng.pc libpng-config
 
 # Make this to verify that "make [...] install" will do what you want.
 buildsetup-tell:
@@ -145,8 +121,12 @@
 libpng.pc: scripts/libpng.pc.in
 	@echo -e Making pkg-config file for this libpng installation..'\n' \
            using PREFIX=\"$(prefix)\"'\n'
-	cat $(S)/scripts/libpng.pc.in | sed -e s\!@PREFIX@!$(prefix)! | \
-	   sed -e s/-lm// > libpng.pc
+	cat scripts/libpng.pc.in | sed -e s!@prefix@!$(prefix)! \
+	-e s!@exec_prefix@!$(exec_prefix)! \
+	-e s!@libdir@!$(LIBPATH)! \
+	-e s!@includedir@!$(INCPATH)! \
+	-e s!@includedir@!$(INCPATH)! \
+	-e s!-lpng14!-lpng14\ -lz\ -lm! > libpng.pc
 
 libpng-config: scripts/libpng-config-head.in scripts/libpng-config-body.in
 	@echo -e Making $(LIBNAME) libpng-config file for this libpng \
@@ -168,7 +148,7 @@
 	$(AR) rc $@ $(OBJS)
 	$(RANLIB) $@
 
-$(SHAREDDEF): scripts/pngwin.def
+$(SHAREDDEF): scripts/pngw32.def
 	cat $< | sed -e '1{G;s/^\(.*\)\(\n\)/EXPORTS/;};2,/^EXPORTS/d' | \
 	sed -e 's/\([^;]*\);/;/' > $@
 
@@ -278,24 +258,20 @@
 
 # DO NOT DELETE THIS LINE -- make depend depends on it.
 
-png.o png.pic.o:		png.h pngconf.h pngpriv.h pngdefs.h png.c
-pngerror.o pngerror.pic.o:	png.h pngconf.h pngpriv.h pngdefs.h pngerror.c
-pngrio.o pngrio.pic.o:		png.h pngconf.h pngpriv.h pngdefs.h pngrio.c
-pngwio.o pngwio.pic.o:		png.h pngconf.h pngpriv.h pngdefs.h pngwio.c
-pngmem.o pngmem.pic.o:		png.h pngconf.h pngpriv.h pngdefs.h pngmem.c
-pngset.o pngset.pic.o:		png.h pngconf.h pngpriv.h pngdefs.h pngset.c
-pngget.o pngget.pic.o:		png.h pngconf.h pngpriv.h pngdefs.h pngget.c
-pngread.o pngread.pic.o:	png.h pngconf.h pngpriv.h pngdefs.h pngread.c
-pngrtran.o pngrtran.pic.o:	png.h pngconf.h pngpriv.h pngdefs.h pngrtran.c
-pngrutil.o pngrutil.pic.o:	png.h pngconf.h pngpriv.h pngdefs.h pngrutil.c
-pngtrans.o pngtrans.pic.o:	png.h pngconf.h pngpriv.h pngdefs.h pngtrans.c
-pngwrite.o pngwrite.pic.o:	png.h pngconf.h pngpriv.h pngdefs.h pngwrite.c
-pngwtran.o pngwtran.pic.o:	png.h pngconf.h pngpriv.h pngdefs.h pngwtran.c
-pngwutil.o pngwutil.pic.o:	png.h pngconf.h pngpriv.h pngdefs.h pngwutil.c
-pngpread.o pngpread.pic.o:	png.h pngconf.h pngpriv.h pngdefs.h pngpread.c
-pnggccrd.o pnggccrd.pic.o:	png.h pngconf.h pngpriv.h pngdefs.h pnggccrd.c
+png.o png.pic.o:		png.h pngconf.h pngpriv.h png.c
+pngerror.o pngerror.pic.o:	png.h pngconf.h pngpriv.h pngerror.c
+pngrio.o pngrio.pic.o:		png.h pngconf.h pngpriv.h pngrio.c
+pngwio.o pngwio.pic.o:		png.h pngconf.h pngpriv.h pngwio.c
+pngmem.o pngmem.pic.o:		png.h pngconf.h pngpriv.h pngmem.c
+pngset.o pngset.pic.o:		png.h pngconf.h pngpriv.h pngset.c
+pngget.o pngget.pic.o:		png.h pngconf.h pngpriv.h pngget.c
+pngread.o pngread.pic.o:	png.h pngconf.h pngpriv.h pngread.c
+pngrtran.o pngrtran.pic.o:	png.h pngconf.h pngpriv.h pngrtran.c
+pngrutil.o pngrutil.pic.o:	png.h pngconf.h pngpriv.h pngrutil.c
+pngtrans.o pngtrans.pic.o:	png.h pngconf.h pngpriv.h pngtrans.c
+pngwrite.o pngwrite.pic.o:	png.h pngconf.h pngpriv.h pngwrite.c
+pngwtran.o pngwtran.pic.o:	png.h pngconf.h pngpriv.h pngwtran.c
+pngwutil.o pngwutil.pic.o:	png.h pngconf.h pngpriv.h pngwutil.c
+pngpread.o pngpread.pic.o:	png.h pngconf.h pngpriv.h pngpread.c
 
-pngtest.o pngtest.pic.o:	png.h pngconf.h pngpriv.h pngdefs.h pngtest.c
-
-
-
+pngtest.o pngtest.pic.o:	png.h pngconf.h pngpriv.h pngtest.c