Feature request: Ability to set a "soft limit"

[geckoseo]

Hi,

This addon would have been more useful to me if there was an option to set a soft limit, so that once the limit is exceeded it doesn't prevent further input, and rather displays a warning, or appends a class to the field so we can change the background colour.

I've been using the jQuery Text Counter Plugin v0.8.0 plugin up to now, which allows me to do this, but of course the nice thing with the metabox limiter is that it can be set up directly via the field settings rather than custom coding it each time.

https://github.com/ractoon/jQuery-Text-Counter