Implement blargg ntsc filters

- this implements blargg's nes ntsc filters using core options
- an optional height doubling is also added but disabled for performance reasons (might make that optional as a core option)
- since PS2 and PSP have their own blitter branches, these platforms do not have the ntsc filters since i dont have the means to test on those systems.
- compile with HAVE_NTSC=1 to have these options, HAVE_NTSC=0 disabled filter including core options
- HAVE_NTSC=1 is set as default, other than PS2 and PSP as stated above.

Makefile.libretro

@@ -5,6 +5,7 @@ HAVE_GRIFFIN=1
 STATIC_LINKING=0
 ENDIANNESS_DEFINES=
 SIGNED_CHAR=0
+HAVE_NTSC=1
 
 SPACE :=
 SPACE := $(SPACE) $(SPACE)
@@ -180,6 +181,7 @@ else ifeq ($(platform), ps2)
 	EXTERNAL_ZLIB=1
 
 	RETROARCH_OBJECTS +=  ps2/SMS_Utils.o
+	HAVE_NTSC = 0
 
 # PSP
 else ifeq ($(platform), psp1)
@@ -192,6 +194,7 @@ else ifeq ($(platform), psp1)
 	PLATFORM_DEFINES += -falign-functions=32 -falign-loops -falign-labels -falign-jumps
 	STATIC_LINKING=1
 	EXTERNAL_ZLIB=1
+	HAVE_NTSC = 0
 
 # Vita
 else ifeq ($(platform), vita)