Cleanup patch: Change from Vector/Hashtable to ArrayList/HashMap

Hi,

Here are two small cleanup patches.

First one replaces all Vector references with List (usage) and ArrayList (creation).
Second replaces all Hashtable references with Map (usage) and HashMap (creation).

Reasons:
* Theoretically faster since the ArrayList/HashMap are not synchronized
* Using interfaces makes changing of List/Map implementations easier at later time
* Vector/Hashtable were deprecated already in Java 1.2

-Mikko