A new message option.

An alternative way to provide the message text, i.e.
message: 'You have typed %charsTyped% chars, %charsRemaining% of %charsTotal% remaining'
%charsTyped%, %charsRemaining% and %charsTotal% will be replaced by the actual values.
This overrides the options separator, preText, postText and showMaxLength.
This makes it easier to do i18n.

I used uglify.js to create the minified version.