Refactor `option map predicate getOrElse false`
Remove xforms-invalid-visited class

No longer needed as IE6 is no longer supported.
Remove `display: -moz-inline-box`
Remove unneeded GIFs
Use black and white asterisk when field is required and filled
For #794: Pass constraint information to client for styling

- place constraint classes on control and external alert
- add xforms-active on alert
- remove xforms-alert-active-visited, xforms-alert-active and xforms-alert-inactive on alert
- Ajax: update constraint level
- use different colors for warning and info