Add icon-lamp; Create new highlight message box
Propose booking for the next day after 17:30

 - Automatically set the booking start time at the current time (rounded up to 15 minutes) after 8:30
 - Automatically set the booking on the next day after 17:30 except if today's date is explicitly explicitely specified (for the simple booking, via the query string)
 - Fix bug in parsing dates in the query string of the simple booking
 - Fixes #1521
Post fix changes for #1521 and highlight msg box
Don't show date_changed msg if form submitted
Don't show datechange msg if loaded from jstorage

When we loaded another date from jStorage the message is most
likely invalid so we don't even show it.