Make Production Mode settings configurable

It would be great if the production mode form had a bit more flexibility.

For example, I have worked on sites where Javascript Aggregation broke the site or the site uses something like Adv Agg to handle aggregation. It would be great to get the production mode settings changes so they're configurable.

Similarly, there is a list of hardcoded modules to disable in prod_check_prod_mode_modules(). Again, it would be cool to expose that list in a text area and allow the user to add/subtract modules from the list.