Shader uniforms keep their values after love.window.setMode (resolves issue #1174).

Also allow arrays of images/samplers in shaders, although driver support is iffy and you have to index into the array using a compile-time constant (which might exclude loop indexing).

--HG--
branch : minor

src/modules/graphics/opengl/Image.cpp

@@ -281,6 +281,9 @@ void Image::loadFromImageData()
 
 bool Image::loadVolatile()
 {
+	if (texture != 0)
+		return true;
+
 	OpenGL::TempDebugGroup debuggroup("Image load");
 
 	if (isCompressed() && !hasCompressedTextureSupport(cdata[0]->getFormat(), sRGB))