Implemented entity.GetType() in lua

This will only work for userdata decented from the Entity base class.
Using something else results in undefined behavior.

server/characters/character_data.cpp

@@ -21,6 +21,10 @@
 */
 #include "character_data.hpp"
 
+CharacterData::CharacterData(): Entity("character") {
+	//EMPTY
+}
+
 int CharacterData::GetOwner() {
 	return owner;
 }