C++11: Cleaned up commands code with range-based for

src/commands/CmdCalc.cpp

@@ -64,9 +64,8 @@ int CmdCalc::execute (std::string& output)
   // Compile all the args into one expression.
   std::string expression;
   std::vector <std::string> words = context.cli.getWords ();
-  std::vector <std::string>::iterator word;
-  for (word = words.begin (); word != words.end (); ++word)
-    expression += *word + " ";
+  for (auto& word : words)
+    expression += word + " ";
 
   // Evaluate according to preference.
   Variant result;