Allow rulebook director to turn proposal creation on or off.

The goal is to have a period in the beginning of the rulebook committee where proposal creation is not an option. This is to encourage discussion. Also, after a few months, we want to turn off proposal creation again in order to wrap up the committee.

I was able to create the boolean in the rulebook table but am having trouble implementing the feature. **The pulled code does not work.** Specifically, the rulebook variable is not being passed into the ability model but I'm not sure how to fix this, or if there is a different approach entirely which would be better.