Start implementing XEP-0084

So far we just subscribe and get the IDs.

src/event/server_events.c

@@ -54,6 +54,7 @@
 #include "xmpp/muc.h"
 #include "xmpp/chat_session.h"
 #include "xmpp/roster_list.h"
+#include "xmpp/avatar.h"
 
 #ifdef HAVE_LIBOTR
 #include "otr/otr.h"
@@ -90,6 +91,8 @@ sv_ev_login_account_success(char *account_name, gboolean secured)
     omemo_on_connect(account);
 #endif
 
+    avatar_pep_subscribe();
+
     ui_handle_login_account_success(account, secured);
 
     // attempt to rejoin all rooms