Derive the class wrapping std::vector<> in Java from java.util.AbstractList<>.
This makes it possible to use it with various algorithms working with Java
collections and, maybe even more importantly, makes it possible to iterate
over the wrapped vectors using for-each loops.
This commit is based on the original patch by Volker Diels-Grabsch from
https://sourceforge.net/p/swig/patches/278/
