* Fixing compilation issue with gcc

NPLib/Utility/nponline.cxx

 #include"TApplication.h"
 #include"NPOnline.h"
-
+#include<cstdlib>
 int main(int argc , char** argv){
   TApplication* app = new TApplication("NPOnline",0,0);
   if(argc==3){
-   NPL::NPOnline* instance = new NPL::NPOnline(argv[1],atoi(argv[2]));
+   NPL::NPOnline* instance = new NPL::NPOnline(argv[1],std::atoi(argv[2]));
   }
   else{
     NPL::NPOnline* instance = new NPL::NPOnline();