Fix alias to keep old rule and add new one instead of updating old rule.

Alias was broken because it when an alias was made the old path was completely
removed and there was no way to specify it.  Update it so aliases just add
an new duplicate rule instead.

parser/parser.h

@@ -53,6 +53,8 @@ struct cod_entry {
 	int audit;			/* audit flags for mode */
 	int deny;			/* TRUE or FALSE */
 
+	int alias_ignore;		/* ignore for alias processing */
+
 	int subset;
 
 	pattern_t pattern_type;