Resize constrain on axis

A great feature would be to allow someone to constrain resize on an axis. It's an easy feature to build.

For instance, say there was a config.constrainWidth setting, then in theme.js resize = function():

if (!this.config.constrainWidth) {
CKEDITOR.env.webkit && outer.setStyle('display', 'none');
outer.setStyle('width', width);
if (CKEDITOR.env.webkit)
{
outer.$.offsetWidth;
outer.setStyle('display', '');
}
}