Bug 13421: Add the creation time for virtual shelves

Bug 13421: Add the creation time for virtual shelves

Test plan:
1/ Execute the updatedb entry
2/ Create a list
3/ Go on the shelve list and confirm that the creation and last
modification time are now displayed.
4/ Confirm that you are able to sort the list by creation/modification
time.

Applied on top of 13419 (rebased updatedatabase.pl)
Works as expected.
Signed-off-by: Marc Veron <veron@veron.ch>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@gmail.com>