Changes to formats to make millisecond element optional. #42
Revert "Changes to formats to make millisecond element optional. #42"

This reverts commit 1191a88925cbf72ee2434ee682d3216025f67f5c.
Library and test changes for issue #42.

The millisecond element is optional for strings validated against the
"date-time" format.
Merge pull request #43 from egrove/master

Fix for issue #42; Milliseconds optional for "date-time" format.