Work in progress; does not compile!
Moved script registration function to static gamedll libs instead, and used a pointer callback approach for calling them to avoid duplicate symbols during linkage.
Reason parameters are optional. For scripts, to use the default message, pass in an empty string. The function for the script system should be centralized soon to avoid more duplicate code.
Properly decouple squirrel and game code. This makes it easier to reverse engineer more of this squirrel system, and to compile them as individual libraries later on when moving to CMake to significantly decrease compile times.
