Some very basic zipper benchmarks.

Issue #121.

Signed-off-by: Austin Seipp <mad.one@gmail.com>
Add benchmarks for zipper creation and a basic traversal.

Issue #121.

Signed-off-by: Austin Seipp <mad.one@gmail.com>
Add tugTo to rezipping benchmark. Issue #121.

Signed-off-by: Austin Seipp <mad.one@gmail.com>
More documentation for Zipper. Doctests for 'moveTo.'

Issue #122.

Signed-off-by: Austin Seipp <mad.one@gmail.com>