Currently, we use a peculiar mapping of ESM classes by their std::type_info::name. This mapping is an undefined behaviour because std::type_info::name is strictly implementation defined. It could return a non-unique value on some platforms. With this PR we use the unsigned int sRecordId of the ESM class as a more efficient lookup type that does not build on undefined behaviour. We can expect marginally faster save-game loading with these changes as well.
