Use shared_ptr and references for Actions.

This slows terminal emulation slightly.

src/terminal/parsertransition.h

@@ -45,7 +45,7 @@ namespace Parser {
   public:
     // Transition is only a courier for an Action; it should
     // never create/delete one on its own.
-    Action *action;
+    ActionPointer action;
     State *next_state;
 
     Transition( const Transition &x )
@@ -58,20 +58,14 @@ namespace Parser {
 
       return *this;
     }
-    virtual ~Transition()
-    {
-      // Indicate to checkers that we don't own *action anymore
-      action = NULL;
-    }
-
-    Transition( Action *s_action=new Ignore, State *s_next_state=NULL )
+    Transition( ActionPointer s_action=shared::make_shared< Ignore >(), State *s_next_state=NULL )
       : action( s_action ), next_state( s_next_state )
     {}
 
     // This is only ever used in the 1-argument form;
     // we use this instead of an initializer to
     // tell Coverity the object never owns *action.
-    Transition( State *s_next_state, Action *s_action=new Ignore )
+    Transition( State *s_next_state, ActionPointer s_action=shared::make_shared< Ignore >() )
       : action( s_action ), next_state( s_next_state )
     {}
   };