Fix start-date with separate fields for IE8.
Fix start-date with separate fields for IE8.

IE8 expected the datetime format to be different, i.e. not separated by dashes.

jcherniak/jquery.recurrenceinput.js,collective/jquery.recurrenceinput.js,jcherniak/jquery.recurrenceinput.js,collective/jquery.recurrenceinput.js,collective/jquery.recurrenceinput.js,jcherniak/jquery.recurrenceinput.js