Add Valgrind to CI

* Also pass `$*` to `configure` when invoking `ci-build.sh`, so one can
  e.g. run `./ci-build.sh --without-xscreensaver`

Signed-off-by: Steffen Jaeckel <s@jaeckel.eu>

src/xmpp/chat_session.c

@@ -89,7 +89,7 @@ void
 chat_sessions_clear(void)
 {
     if (sessions) {
-        g_hash_table_remove_all(sessions);
+        g_hash_table_destroy(sessions);
         sessions = NULL;
     }
 }

src/xmpp/muc.c

@@ -94,14 +94,14 @@ static void _occupant_free(Occupant* occupant);
 static void
 _muc_close(void)
 {
-    autocomplete_free(invite_ac);
-    autocomplete_free(confservers_ac);
-    g_hash_table_destroy(rooms);
     g_hash_table_destroy(invite_passwords);
-    rooms = NULL;
     invite_passwords = NULL;
-    invite_ac = NULL;
+    g_hash_table_destroy(rooms);
+    rooms = NULL;
+    autocomplete_free(confservers_ac);
     confservers_ac = NULL;
+    autocomplete_free(invite_ac);
+    invite_ac = NULL;
 }
 
 void