Reduce cost of including chaiscript.hpp

- ChaiScript no longer includes or automatically instantiates std lib
 - ChaiScript constructor now requires an std lib instance in the form
   of a ModulePtr object
 - This new layout facilitates better usage of compilation firewalls and
   factories for reducing the overall impact of ChaiScript on a project

src/main.cpp

@@ -10,6 +10,7 @@
 
 #define _CRT_SECURE_NO_WARNINGS
 #include <chaiscript/chaiscript.hpp>
+#include <chaiscript/chaiscript_stdlib.hpp>
 
 #ifdef READLINE_AVAILABLE
 #include <readline/readline.h>
@@ -176,7 +177,7 @@ int main(int argc, char *argv[])
     modulepaths.push_back(modulepath);
   }
 
-  chaiscript::ChaiScript chai(modulepaths,usepaths);
+  chaiscript::ChaiScript chai(chaiscript::Std_Lib::library(), modulepaths,usepaths);
 
   chai.add(chaiscript::fun(&myexit), "exit");
   chai.add(chaiscript::fun(&myexit), "quit");