Add Custom User field option to hide custom field from signup dialogue

Sometimes it is nice to have a bunch of custom user fields to ask for information that you don’t want to bother people with on signup. For example, you might want to have the ability for someone to provide their address, zip code, or hair color, but on signup ask them only for their name and email address.

This is possible now by using a theme component to hide all custom fields and then un-hide the ones you want. It would be nice if there were a checkbox in the custom user field settings.