Updated html5Forms.js to support extra CSS features:
Added information about CSS classes supported that are not part of the
CSS3 UI specification.
1) Made reset button clear custom validation classes.
2) Added an data attribute for the html5Forms.js script tag,
data-webforms2-force-js-date-picker, which, when set to "true" will
force the js implementation of type="date".  This is to work around
Chrome's current incomplete implementation of date fields (it doesn't
support datetime, the display format is different to what is submitted,
etc)
Copy changes.
Fixed issue with finding erroneous script html5Forms.js script tag.
Added force js datepicker example.