fix(dateparser): Throw on invalid date format string.

[stevecavanagh]

This PR replaces #3568. The dateParser will throw an exception for an invalid format string. In addition to fixing some code formatting issues, this PR also handles parsing dates from the datepicker with a datetime-local type.

[stevecavanagh]

Closing due to lint failure. Resubmitted PR #3691.

[realityking]

@stevecavanagh Just a FYI, you don't have to open a new pull request if you need to change something. Just push again into the same branch and it will be picked up.

If you want/need to keep it to one commit take a look at amending and rebasing

[stevecavanagh]

Sorry, I was under the mistaken belief that I shouldn't amend/rebase after I've pushed. Thank you, I'll follow that approach going forward.

[realityking]

@stevecavanagh That's a good rule for public repositories, otherwise calloboration withothers (or even forks) are in hell. For branches that only serve as the base for a pull request, that doesn't matter as you'll be the only one pushing into it.