Add ability to disable loading external files

* Options are passed to ChaiScript constructor
 * load_module / eval_file / use can be disabled
   from script context

include/chaiscript/chaiscript.hpp

@@ -827,11 +827,12 @@ namespace chaiscript
   {
     public:
       ChaiScript(std::vector<std::string> t_modulepaths = {},
-          std::vector<std::string> t_usepaths = {})
+          std::vector<std::string> t_usepaths = {},
+          const std::vector<Options> &t_opts)
         : ChaiScript_Basic(
             chaiscript::Std_Lib::library(),
             std::make_unique<parser::ChaiScript_Parser<eval::Noop_Tracer, optimizer::Optimizer_Default>>(),
-            t_modulepaths, t_usepaths)
+            t_modulepaths, t_usepaths, t_opts)
         {
         }
   };