Fix availability for damaged

Signed-off-by: Dimitris Aragiorgis <dimara@grnet.gr>
Fix "too many sql variables" error

First filter then prefetch_related.

Signed-off-by: Dimitris Aragiorgis <dimara@grnet.gr>
info: first filter then prefetch

Signed-off-by: Dimitris Aragiorgis <dimara@grnet.gr>
Use custom ReservationForm in Appartments

Signed-off-by: Dimitris Aragiorgis <dimara@grnet.gr>
Add hyperlink for staff in parousiologio

Signed-off-by: Dimitris Aragiorgis <dimara@grnet.gr>
Remove useless search_fields from Staff

Signed-off-by: Dimitris Aragiorgis <dimara@grnet.gr>