[FEATURE] Add a time field to the Date Picker of datetime fields

This change adds a specialized Date Picker, which is used for datetime fields.
Previously, always 0:00 has been returned as time of the day.

Change-Id: I2be56f5ecb56edd9c5619ae3bbf6d8cb8a091768
Resolves: #M17596
Reviewed-on: http://review.typo3.org/1184


Reviewed-by: Steffen Kamper <info@sk-typo3.de>
Tested-by: Steffen Kamper <info@sk-typo3.de>