Abstract implementation of {@link Cursor}. Java's {@link java.util.Iterator}interface is implemented by mapping to abstract {@link #fwd()} and{@link #get()}.
For localization, default implementations are available that all build on the abstract int variant. For particular cursors, this may be implemented more efficiently saving at least one loop over n.
This is identical to {@link AbstractCursor}, except that default implementations build on the abstract int instead of long variant here.
@param < T>
@author Stephan Preibisch
@author Stephan Saalfeld
@author Tobias Pietzsch