Add option to make Maxlength non restrictive

Hello,
first of all, thanks for your module.

I'd like to have the possibility to choose if Maxlength is restrictive or not. The idea is to leave the possibility to save a node even if a field has exceeded the max length value set in the field's settings.
In a way, leave the display of the max length countdown, but "bypass" the form_error(), to be able to save the node anyway.

I didn't find any issue about it and didn't find also the right way to do it in the code.

Maybe if you put me in the right direction, and give me some hints, I'll be glad to try to do it and, if I succeed, create a patch for it.

Have a nice day.