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.
* modsystem v2 initial commit
* call CModSystem::Init
* clean up custom cvar value handling
* add mod script compiling support
* add error check to script rson loading
yes this error is a duplicate but this one exits the game
* fix typo
* fix compile error
