Fix duplicate w_POWER definition

Fix duplicate w_POWER definition and some house keeping. Tested the new
commit by @AngelaMarchi from #87, all results are the same as version
2.1.

src/types.h

@@ -506,7 +506,7 @@ struct  ActItem *ActList;   /* Linked list of action items */
 int     RuleState;          /* State of rule interpreter */
 long    Time1;              /* Start of rule evaluation time interval (sec) */
 struct  Premise *Plast;     /* Previous premise clause */
-struct  Action *Tlast; /*Previous true action */ 
-struct  Action *Flast; /*Previous false action */ 
+struct  Action *Tlast;      /* Previous true action */ 
+struct  Action *Flast;      /* Previous false action */ 
 
 #endif