Implement Array, Cubemap, and Volume texture types (issue #1111).

- Add love.graphics.newArrayImage, newCubeImage, and newVolumeImage.
- Add love.graphics.newCanvas(w, h, layers) and newCanvas(w, h, layers, settings). Add ‘type’ field to the settings table of newCanvas.

- Add new love.graphics.setCanvas variants: setCanvas(canvas, slice), and setCanvas(canvastable) where canvastable is in the format: {{canvas1, layer=2}, {canvas2, face=5}}

- Add Texture:getTextureType, getDepth, getLayerCount, getMipmapCount, and getFormat.

- Remove Image:getData and Image:refresh.
- Add Image:replacePixels(imagedata [, slice] [, mipmap]).

- Update Canvas:newImageData to accept a slice argument.

- Add love.image.newCubeFaces(imagedata).

--HG--
branch : minor

src/modules/image/magpie/PKMHandler.h

@@ -41,8 +41,11 @@ public:
 	virtual ~PKMHandler() {}
 
 	// Implements CompressedFormatHandler.
-	virtual bool canParse(const filesystem::FileData *data);
-	virtual uint8 *parse(filesystem::FileData *filedata, std::vector<CompressedImageData::SubImage> &images, size_t &dataSize, PixelFormat &format, bool &sRGB);
+	bool canParse(const filesystem::FileData *data) override;
+
+	StrongRef<CompressedImageData::Memory> parse(filesystem::FileData *filedata,
+	        std::vector<StrongRef<CompressedImageData::Slice>> &images,
+	        PixelFormat &format, bool &sRGB) override;
 
 }; // PKMHandler