Don't raise MaKaCError for bad event data

It's user input so it should be FormValuesError!
NoReportError in Room checks based on user input

check_bookable_hours, check_advance_days
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