Notify AbstractTreeIterator implementations of skipped tree entries
Some tree iterators may benefit from knowing when their driving TreeWalk
has chosen to skip past their current entry and not report it to client
applications. This can be useful for an index update scenario where the
client application has applied a TreeFilter to only see the entries that
it wants to modify in this session.
By default the new skip() method just calls next(), as most types of the
tree iterator do not have this distinction between skipped entry and a
non-skipped entry.
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Robin Rosenberg <robin.rosenberg@dewire.com>