other / mew-iview

We have too many use cases and we cannot access props inside validator
function, so we cannot do proper checking anyway

refactor Datepicker  to render subcomponents in template instead of
creating new Vue instances

Return empty string if the date input doesn't parse

This ads the possibility to choose `steps` in the formatting of the
lists. So we can have ”5 in five minutes” or ”every 15 minutes” instead
of having always lists of 60 items/minutes.