Enhancement - _commands

- Added undocumented _commands command to support completion scripts.

src/command.cpp

@@ -315,6 +315,20 @@ std::string handleCompletionTags ()
   return out.str ();
 }
 
+////////////////////////////////////////////////////////////////////////////////
+std::string handleCompletionCommands ()
+{
+  std::vector <std::string> commands;
+  context.cmd.allCommands (commands);
+  std::sort (commands.begin (), commands.end ());
+
+  std::stringstream out;
+  foreach (command, commands)
+    out << *command << std::endl;
+
+  return out.str ();
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 void handleUndo ()
 {