aco: Minimize use of regex.

Remove nearly all use of regex from ACO users.  Still remaining:
* app_confbridge has a legitamate use of option name regex.
* ast_sorcery_object_fields_register is implemented with regex, all
  callers use simple prefix based regex.  I haven't decided the best
  way to fix this in both 13/15 and master.

Change-Id: Ib5ed478218d8a661ace4d2eaaea98b59a897974b

channels/chan_motif.c

@@ -541,8 +541,8 @@ static int jingle_endpoint_cmp(void *obj, void *arg, int flags)
 static struct aco_type endpoint_option = {
 	.type = ACO_ITEM,
 	.name = "endpoint",
-	.category_match = ACO_BLACKLIST,
-	.category = "^general$",
+	.category_match = ACO_BLACKLIST_EXACT,
+	.category = "general",
 	.item_alloc = jingle_endpoint_alloc,
 	.item_find = jingle_endpoint_find,
 	.item_offset = offsetof(struct jingle_config, endpoints),