Ticket 475 - Root DN Access Control - improve value checking for config
Bug Description: Plugin was not checking the time values, and the "allowed-days"
Fix Description: Make sure the open and close times are with 0000-2359, and make
sure that each day in "rootdn-days-allowed" is a valid day.
https://fedorahosted.org/389/ticket/475
Reviewed by: noriko(Thanks!)