Fix incorrect default port.
Merge pull request #14 from Reisen/master

Fix incorrect default port.
Make iterator support empty batches.  This fixes #13
Do not output url to stdout.
Merge pull request #15 from blackbeam/do-not-print-url

Do not output url to stdout.
fail -> panic
Merge pull request #16 from steveklabnik/master

fail -> panic
Added note on nightly
Made it work with latest nightly