[hl] Move hl.Format to format.hl.Native (#112)

* [hl] Move hl.Format to format.hl.Native

* Guard native inside if hl

* Fix package name

format/hl/Native.hx

@@ -0,0 +1,56 @@
+package format.hl;
+
+enum abstract PixelFormat(Int) {
+	var RGB = 0;
+	var BGR = 1;
+	var RGBX = 2;
+	var BGRX = 3;
+	var XBGR = 4;
+	var XRGB = 5;
+	var GRAY = 6;
+	var RGBA = 7;
+	var BGRA = 8;
+	var ABGR = 9;
+	var ARGB = 10;
+	var CMYK = 11;
+}
+
+class Native {
+
+#if hl
+	/**
+		Decode JPG data into the target buffer.
+	**/
+	@:hlNative("fmt", "jpg_decode")
+	public static function decodeJPG(src:hl.Bytes, srcLen:Int, dst:hl.Bytes, width:Int, height:Int, stride:Int, format:PixelFormat, flags:Int):Bool {
+		return false;
+	}
+
+	/**
+		Decode PNG data into the target buffer.
+	**/
+	@:hlNative("fmt", "png_decode")
+	public static function decodePNG(src:hl.Bytes, srcLen:Int, dst:hl.Bytes, width:Int, height:Int, stride:Int, format:PixelFormat, flags:Int):Bool {
+		return false;
+	}
+
+	/**
+		Decode any image data into ARGB pixels
+	**/
+	#if (hl_ver >= version("1.10.0"))
+	@:hlNative("fmt", "dxt_decode")
+	public static function decodeDXT(src:hl.Bytes, dst:hl.Bytes, width:Int, height:Int, dxtFormat:Int):Bool {
+		return false;
+	}
+	#end
+
+	/**
+		Upscale/downscale an image.
+		Currently supported flag bits: 1 = bilinear filtering
+	**/
+	@:hlNative("fmt", "img_scale")
+	public static function scaleImage(out:hl.Bytes, outPos:Int, outStride:Int, outWidth:Int, outHeight:Int, _in:hl.Bytes, inPos:Int, inStride:Int,
+		inWidth:Int, inHeight:Int, flags:Int) {}
+
+#end
+}