Array textures can be easily drawn without a shader (resolves issue #1111).

Added love.graphics.drawLayer(texture, layerindex, …). ‘texture’ must be an array texture.
Added SpriteBatch:add/setLayer.

Added Quad:get/setLayer. This applies to array textures that are drawn without specifying an explicit layer index in the draw call.

Added love.graphics.newQuad variants which have layer arguments.

--HG--
branch : minor

src/modules/graphics/wrap_Graphics.lua

@@ -412,6 +412,11 @@ vec4 effect(vec4 vcolor, Image tex, vec2 texcoord, vec2 pixcoord) {
 	videopixel = [[
 vec4 effect(vec4 vcolor, Image tex, vec2 texcoord, vec2 pixcoord) {
 	return VideoTexel(texcoord) * vcolor;
+}]],
+	arraypixel = [[
+uniform ArrayImage MainTex;
+void effect() {
+	love_PixelColor = Texel(MainTex, VaryingTexCoord.xyz) * VaryingColor;
 }]],
 }
 
@@ -432,6 +437,7 @@ for lang, info in pairs(langs) do
 			vertex = createShaderStageCode("VERTEX", defaultcode.vertex, info.target, info.gles, false, gammacorrect),
 			pixel = createShaderStageCode("PIXEL", defaultcode.pixel, info.target, info.gles, false, gammacorrect, false),
 			videopixel = createShaderStageCode("PIXEL", defaultcode.videopixel, info.target, info.gles, false, gammacorrect, false),
+			arraypixel = createShaderStageCode("PIXEL", defaultcode.arraypixel, info.target, info.gles, false, gammacorrect, true),
 		}
 	end
 end