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

--HG--
branch : dynamiccore2

src/modules/graphics/opengl/Shader.cpp

@@ -62,6 +62,7 @@ namespace
 } // anonymous namespace
 
 
+love::Type Shader::type(&Object::type);
 Shader *Shader::current = nullptr;
 Shader *Shader::defaultShader = nullptr;
 Shader *Shader::defaultVideoShader = nullptr;