front end optimization&stack overflow prompt

change parameter type to avoid unnecessary copies of string.
change stack depth from 65536<<4 to 16+(65536<<2).
now you could know stack overflow when it happens

main.cpp

@@ -28,7 +28,7 @@ void logo()
     return;
 }
 
-void die(std::string stage,std::string filename)
+void die(const char* stage,std::string& filename)
 {
 	std::cout<<">> ["<<stage<<"] in <\""<<filename<<"\">: error(s) occurred,stop.\n";
 	return;