Added showDefaultTime Config

We needed the ability to have a time show up in the widget, but not the input field; I added a showDefaultTime configuration that, when set to false (default is true), will prevent the time from getting set in the input field until the widget is shown, at which point it calls the update function to synch the two.  I added unit tests, though I don't have a lot of experience with unit testing, so I'm happy to update those as appropriate.