make use of post instead of get

apps/calendar/ajax/calendar/edit.form.php

apps/calendar/ajax/changeview.php

apps/calendar/ajax/event/edit.form.php

apps/calendar/ajax/import/import.php

apps/calendar/ajax/settings/guesstimezone.php

apps/calendar/ajax/share/activation.php

apps/calendar/ajax/share/changepermission.php

apps/calendar/ajax/share/dropdown.php

apps/calendar/ajax/share/share.php

apps/calendar/ajax/share/unshare.php

apps/calendar/js/calendar.js

apps/calendar/js/geo.js

apps/calendar/js/loader.js