Fail fast if a collection is modified during marshalling

If a collection is modified by a different thread during marshalling, the serialization usually fails with a ConcurrentModificationException. But in rare cases, MarshallUti.marshallCollection() may succeed to write a size of X and then Y elements.

MarshallUti.marshallCollection() could keep track of how many elements it writes and throw an exception at the end if the number of elements it wrote is different from the size it wrote.