Textarea maxlength attribute prematurely ends text input with html tags

Problem

By default, the textarea field is assigned the maxlength attribute. maxlength.js accounts for html tags by regexing them and removing them from the character count, but this is still constrained by the maxlength attribute on the textarea element.

E.g.

<textarea maxlength="300"> ..etc... </textarea>

The js will correctly parse out tags for the character count, but the field itself still considers the tags in applying max length, causing a mismatch between input and feedback.

Proposed solution

Potential fix attached in patch: move the maxlength attribute to a data-maxlength attribute; re-apply the maxlength attribute when necessary.