Improving contacts

apps/contacts/ajax/addproperty.php

apps/contacts/ajax/deleteproperty.php

apps/contacts/ajax/getdetails.php

apps/contacts/ajax/setproperty.php

apps/contacts/ajax/showsetproperty.php

apps/contacts/index.php

apps/contacts/js/interface.js

apps/contacts/l10n/.gitkeep

apps/contacts/lib/addressbook.php

apps/contacts/templates/index.php

apps/contacts/templates/part.addcardform.php

apps/contacts/templates/part.details.php

apps/contacts/templates/part.setpropertyform.php