Add vCard support

Only nicknames, photos, birthdays, addresses, telephone numbers, emails,
JIDs, titles, roles, notes, and URLs are supported

Due to the synopsis array not having enough space, `/vcard photo
open-self` and `/vcard photo save-self` are not documented properly in
the synopsis section of the `/vcard` command, but they are documented in
the arguments section

Fixed memory leak in vcard autocomplete (thanks to debXwoody)

src/event/server_events.c

@@ -61,6 +61,7 @@
 #include "xmpp/chat_session.h"
 #include "xmpp/roster_list.h"
 #include "xmpp/avatar.h"
+#include "xmpp/vcard_funcs.h"
 
 #ifdef HAVE_LIBOTR
 #include "otr/otr.h"
@@ -101,7 +102,7 @@ sv_ev_login_account_success(char* account_name, gboolean secured)
 #endif
 
     log_database_init(account);
-
+    vcard_user_refresh();
     avatar_pep_subscribe();
 
     ui_handle_login_account_success(account, secured);