no option to close input-date on select

As stated in the title. I'm aware that it's the default behaviour of `pickadate` provided by materialize and I know it can be hacked by closing it in `onSet` function with jquery, but it would be nice if it was configurable option, especially considering the fact that that's the way the "clean" `pickadate` works by default.

Start at the input-date directive and trace its pickadate integration, including the existing onSet behavior described in the issue. Add a configurable close-on-select option and verify that the default behavior remains unchanged while the option closes the picker after selection.

Written by the indexing model from the issue text.