Fix DatePicker Display Issue

DatePicker was being displayed behind dialog box when adding new entries
to applications.  This was caused by a z-index value being lower for the
DatePicker than that of the dialog box containing it.  This commit bumps
up the z-index value of the DatePicker making it display as intended.
Merge pull request #2 from jtmorris/fix_datepicker

Fix DatePicker Display Issue