appointment date change

When date of the appointment is changed and daily planing had been done for the appointment, appointmentlinks disappear from daily planning. The reason is that in web_appointmenttypelink we store full datetime (not only hour).

We should either change datetime of web_appointmenttypelink when saving appointment. Or store time without date, but this is problematic due to timezones and time change in spring and autumn. Or discard daily planning completly.

I opt for the third options, because together with date they can change hour.