agent: Improve comments for container element types

To allow enhanced grepping for what structs point to other structs.

agent/agent-priv.h

@@ -152,7 +152,7 @@ struct _NiceAgent
   GUPnPSimpleIgdThread* upnp;	   /* GUPnP Single IGD agent */
   gboolean upnp_enabled;           /* whether UPnP discovery is enabled */
   guint upnp_timeout;              /* UPnP discovery timeout */
-  GSList *upnp_mapping;            /* list of Candidates being mapped */
+  GSList *upnp_mapping;            /* NiceAddresses of cands being mapped */
   GSource *upnp_timer_source;      /* source of upnp timeout timer */
 #endif
   gchar *software_attribute;       /* SOFTWARE attribute */

agent/component.h

@@ -140,12 +140,12 @@ struct _Component
   NiceComponentType type;
   guint id;                    /* component id */
   NiceComponentState state;
-  GSList *local_candidates;    /* list of Candidate objs */
-  GSList *remote_candidates;   /* list of Candidate objs */
+  GSList *local_candidates;    /* list of NiceCandidate objs */
+  GSList *remote_candidates;   /* list of NiceCandidate objs */
   GSList *socket_sources;      /* list of SocketSource objs; must only grow monotonically */
   guint socket_sources_age;    /* incremented when socket_sources changes */
   GSList *incoming_checks;     /* list of IncomingCheck objs */
-  GList *turn_servers;             /* List of TURN servers */
+  GList *turn_servers;             /* List of TurnServer objs */
   CandidatePair selected_pair; /* independent from checklists, 
 				    see ICE 11.1. "Sending Media" (ID-19) */
   NiceCandidate *restart_candidate; /* for storing active remote candidate during a restart */

agent/stream.h

@@ -66,7 +66,7 @@ struct _Stream
   guint n_components;
   gboolean initial_binding_request_received;
   GSList *components; /* list of 'Component' structs */
-  GSList *conncheck_list;         /* list of CandidatePair items */
+  GSList *conncheck_list;         /* list of CandidateCheckPair items */
   gchar local_ufrag[NICE_STREAM_MAX_UFRAG];
   gchar local_password[NICE_STREAM_MAX_PWD];
   gchar remote_ufrag[NICE_STREAM_MAX_UFRAG];