MEDIUM: map: uses HAProxy facilities to store default value

The default value is stored in a special struct that describe the
map. This default value is parsed with special parser. This is
useless because HAProxy provides a space to store the default
value (the args) and HAProxy provides also standard parser for
the input types (args again).

This patch remove this special storage and replace it by an argument.
In other way the args of maps are declared as the expected type in
place of strings.

include/types/map.h

@@ -37,9 +37,6 @@ struct map_descriptor {
 	struct sample_conv *conv;      /* original converter descriptor */
 	struct pattern_head pat;       /* the pattern matching associated to the map */
 	int do_free;                   /* set if <pat> is the orignal pat and must be freed */
-	char *default_value;           /* a copy of default value. This copy is
-	                                  useful if the type is str */
-	struct sample_storage *def;    /* contain the default value */
 };
 
 #endif /* _TYPES_MAP_H */