Build type information on first use (load-time), instead of using a hardcoded list

--HG--
branch : dynamiccore2

src/modules/graphics/opengl/Text.cpp

@@ -30,6 +30,8 @@ namespace graphics
 namespace opengl
 {
 
+love::Type Text::type(&Drawable::type);
+
 Text::Text(Font *font, const std::vector<Font::ColoredString> &text)
 	: font(font)
 	, vbo(nullptr)