Replace custom MS types with STL types

The types that need replacing:

• msstring - It's a C style fixed string type. Replacing it with std::string isn't advised since it's dynamically allocated. It'll probably be best to make our fix fixed string inherited from std::basic_string or use a library like this that contains a fixed string.
• msvariant - A variant variable that fits a c string, int, or float
• msstring_ref - Type defined as a const char*
• mslist - a linked list list that is used a vector throughout the code as well. Should be replaced with a std::vector or std::list depending on what should be used there.
• string_i - In debug mode, a normal string. In release mode its created within the engine and released each level
• msnew - Should probably be replaced with just new.

This should be done after angelscript is embedded.

Start by inventorying usages of msstring, msvariant, mslist, msnew, and the other listed custom types after AngelScript is embedded. Review each usage to determine whether an STL replacement is appropriate; done means the custom types targeted by this issue have been replaced without breaking the project.