Argument Parsing

- Obsoleted Command::exectute  'commandLine' argument.  It is worse
  than unnecessary, it is an uncategorized raw argument string, which
  is only really useful for the 'execute' command, which itself now
  calls Arguments::combine to reconstruct the command line string.

src/DOM.cpp

@@ -78,12 +78,12 @@ const std::string DOM::get (const std::string& name)
            name.substr (0, 8) == "context.")
   {
     if (name == "context.program")
-      return context.program;
+      return context.args[0].first;
 
     else if (name == "context.args")
     {
       std::string combined;
-      join (combined, " ", context.args);
+      join (combined, " ", context.args.list ());
       return combined;
     }
     else if (name == "context.width")