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>

tests/unittests/test_muc.c

@@ -6,6 +6,8 @@
 
 #include "xmpp/muc.h"
 
+void prof_shutdown(void);
+
 int
 muc_before_test(void** state)
 {
@@ -16,6 +18,7 @@ muc_before_test(void** state)
 int
 muc_after_test(void** state)
 {
+    prof_shutdown();
     return 0;
 }