Implementation of all current utilities (found in org.neo4j.helpers.collection and
mostly in Iterables and IteratorUtil) into consistent classes split up by
utilities for Iterator and utilities for Iterable.

Most utilities, such as filtering, mapping a.s.o can be accessed both
object-oriented (new MappingIterator { @Override TO map(FROM) } and
functional (map( iterator, new Function<FROM,TO> mapper ).