Fix twisted inside and active methods

Signed-off-by: Dimitris Aragiorgis <dimara@grnet.gr>
Minor changes in templates

Signed-off-by: Dimitris Aragiorgis <dimara@grnet.gr>
Allow a reservation to have no apartment

and include corresponding migration file

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