first revision of sundial

Works with current uploader code, not yet modified to include needed tideline functions.

@jh-bate or @cheddar please review. @cheddar would like me to merge and tag this and have the uploader depend on it before merging the uploader branch where I've removed the moment dependency and replaced it with sundial methods.
This is always ISO but not necessarily Zulu, e.g. it could be '2013-12-31T16:00:00-08:00', equivalent to Zulu time '2014-01-01T00:00:00.000Z'.

That said, I'm going to adjust the test to use the `isISODate` method because that's exactly what that methods checks for.