add missing datatype for correct update in db
fix task form display

* show only name and comments when creating new task
* fix checkbox (it must use the 'checked' attributes instead of using
  values.
small code review on timeslot

* formDeleteEntry() should be renamed showTimeslots() because it is
  first used to display timeslot entries.
* showTimeSlot() must be moved to Timeslot class.
Merge remote-tracking branch 'origin/master' into 0.85+tasks_redux