Added otr_tag_message, removed commands.c dependency on libotr

tests/otr/stub_otr.c

@@ -52,6 +52,11 @@ gboolean otr_key_loaded(void)
     return (gboolean)mock();
 }
 
+char* otr_tag_message(const char * const msg)
+{ 
+    return NULL;
+}
+
 gboolean otr_is_secure(const char * const recipient)
 {
     return FALSE;
@@ -98,4 +103,4 @@ void otr_free_message(char *message) {}
 prof_otrpolicy_t otr_get_policy(const char * const recipient)
 {
     return PROF_OTRPOLICY_MANUAL;
-}
+}