Added png libs to obj directory/added png support to dos port

zsnes/src/link.win32

@@ -1 +1 @@
-/Fezsnesw.exe chips\dsp1proc.obj dos\sw.obj dos\gppro.obj dos\vesa12.obj dos\zsipx.obj dos\modemrtn.obj dos\joy.obj dos\debug.obj dos\vesa2.obj dos\initvid.obj cfgload.obj endmem.obj fixsin.obj init.obj ui.obj vcache.obj water.obj video\procvid.obj win\copyvwin.obj win\winintrf.obj win\winlink.obj win\zloaderw.obj win\ztcp.obj win\zfilew.obj win\zipxw.obj video\makev16b.obj video\makev16t.obj video\makevid.obj video\mode716.obj video\mode716b.obj video\mode716d.obj video\mode716e.obj video\mode716t.obj video\mode7.obj video\mode7ext.obj video\mv16tms.obj video\newg162.obj video\newgfx16.obj video\newgfx2.obj video\newgfx.obj video\m716text.obj video\2xsaiw.obj gui\gui.obj gui\menu.obj cpu\addrni.obj cpu\dma.obj cpu\dsp.obj cpu\dspproc.obj cpu\execute.obj cpu\irq.obj cpu\memory.obj cpu\spc700.obj cpu\stable.obj cpu\table.obj cpu\tableb.obj cpu\tablec.obj chips\dsp1emu.obj chips\fxemu2.obj chips\fxemu2b.obj chips\fxemu2c.obj chips\fxtable.obj chips\sa1proc.obj chips\sa1regs.obj chips\sfxproc.obj zip\unzip.obj zip\zzip.obj zip\zpng.obj libpng.lib zlib.lib wsock32.lib user32.lib gdi32.lib shell32.lib ddraw.lib dsound.lib dinput.lib d3dx.lib /link /section:.text,erw
+/Fezsnesw.exe chips\dsp1proc.obj dos\sw.obj dos\gppro.obj dos\vesa12.obj dos\zsipx.obj dos\modemrtn.obj dos\joy.obj dos\debug.obj dos\vesa2.obj dos\initvid.obj cfgload.obj endmem.obj fixsin.obj init.obj ui.obj vcache.obj water.obj video\procvid.obj win\copyvwin.obj win\winintrf.obj win\winlink.obj win\zloaderw.obj win\ztcp.obj win\zfilew.obj win\zipxw.obj video\makev16b.obj video\makev16t.obj video\makevid.obj video\mode716.obj video\mode716b.obj video\mode716d.obj video\mode716e.obj video\mode716t.obj video\mode7.obj video\mode7ext.obj video\mv16tms.obj video\newg162.obj video\newgfx16.obj video\newgfx2.obj video\newgfx.obj video\m716text.obj video\2xsaiw.obj gui\gui.obj gui\menu.obj cpu\addrni.obj cpu\dma.obj cpu\dsp.obj cpu\dspproc.obj cpu\execute.obj cpu\irq.obj cpu\memory.obj cpu\spc700.obj cpu\stable.obj cpu\table.obj cpu\tableb.obj cpu\tablec.obj chips\dsp1emu.obj chips\fxemu2.obj chips\fxemu2b.obj chips\fxemu2c.obj chips\fxtable.obj chips\sa1proc.obj chips\sa1regs.obj chips\sfxproc.obj zip\unzip.obj zip\zzip.obj zip\zpng.obj obj\libpng.lib zlib.lib wsock32.lib user32.lib gdi32.lib shell32.lib ddraw.lib dsound.lib dinput.lib d3dx.lib /link /section:.text,erw

zsnes/src/makefile.dos

@@ -52,13 +52,13 @@ WINOBJ=${WINDIR}/copywin.o ${WINDIR}/winintrf.o ${WINDIR}/winlink.o\
 
 PREOBJ=${OBJDIR}/dosbuff.o ${OBJDIR}/ipx.o ${OBJDIR}/zipx.o
 
-ZIPOBJ=${ZIPDIR}/zzip.o ${ZIPDIR}/unzip.o
+ZIPOBJ=${ZIPDIR}/zzip.o ${ZIPDIR}/unzip.o ${ZIPDIR}/zpng.obj
 
 MAINOBJ=cfgload.o endmem.o fixsin.o init.o ui.o vcache.o water.o
 
 
 OBJS=${CHIPSOBJ} ${CPUOBJ} ${DOSOBJ} ${GUIOBJ} ${VIDEOBJ} ${PREOBJ} ${MAINOBJ} ${ZIPOBJ}
-LIBS=-lz -lgcc -lm
+LIBS=-lz -lgcc -lm -lpng
 CFLAGS=-D__MSDOS__
 ASM=nasm
 ASMFLAGS=-f coff -D__MSDOS__
@@ -81,7 +81,7 @@ PP=gpp
 ALL: zsnes.exe
 
 zsnes.exe: ${OBJS}
-	${CC} -Ws -s -o zsnes.exe ${OBJS}  ${LIBS}
+	${CC} -Ws -L./obj -s -o zsnes.exe ${OBJS}  ${LIBS}
 
 ${DOSDIR}/zloader.o: ${DOSDIR}/zloader.c
 fixsin.o: fixsin.c
@@ -89,6 +89,7 @@ water.o: water.c
 ${DOSDIR}/zfile.o: ${DOSDIR}/zfile.c
 ${ZIPDIR}/unzip.o: ${ZIPDIR}/unzip.c ${ZIPDIR}/unzip.h
 ${ZIPDIR}/zzip.o: ${ZIPDIR}/zzip.c ${ZIPDIR}/unzip.h
+${ZIPDIR}/zpng.obj: ${ZIPDIR}/zpng.c  ${ZIPDIR}/zpng.h ${ZIPDIR}/png.h
 ${VIDEODIR}/procvid.o: ${VIDEODIR}/procvid.asm macros.mac ${VIDEODIR}/copyvid.inc ${VIDEODIR}/2xSaImmx.inc
 ${CHIPDIR}/dsp1proc.o: ${CHIPDIR}/dsp1proc.asm macros.mac
 ${CHIPDIR}/sa1regs.o: ${CHIPDIR}/sa1regs.asm macros.mac\