ChakraCore support

[kungfooman]

ChakraCore is working now: https://github.com/riicchhaarrd/iw2clientdll/releases

Currently this is adding two extra dlls:

• ChakraCore.dll: recent engine cloned from Microsoft/ChakraCore build for Release/x86

• ChakraCoreInterface.dll: subproject in the ChakraCore solution. Code is not committed currently, will do in short time. It's basically just a little wrapper around ChakraCore.dll, gonna commit the code to this repo to remove this dll

[kungfooman]

little break through, already feels a bit like a proper REPL 😄