Improved NAP terms

@Random good point. We should consider privacy options for NAPs, wars, and alliances. Either all public by default or all private by default.

@Translucent see the “misc details and comments” under #1. Even with something as straightforward as notes, we’ll still have to write some kind of code to ensure that both parties actually agree to what is written.

This all is dependent on NAP Refactoring work that is in progress.