Replace the synchronized class by an unsynchronized in ModuleFilterConfig

Early classes of the Java API, such as Vector, Hashtable and StringBuffer, were synchronized to make them thread-safe. Unfortunately, synchronization has a big negative impact on performance, even when using these collections from a single thread.

It is better to use their new unsynchronized replacements:

ArrayList or LinkedList instead of Vector
Deque instead of Stack
HashMap instead of Hashtable
StringBuilder instead of StringBuffer