Reverse the polarity of the proton flow

[KA101]

Adds a new "is this active mutation turned off?" boolean and applies it to check for NV mutations being turned off, thereby making inactive NV provide the vision and active ones remove it.

Seems backwards, but was specifically requested: http://smf.cataclysmdda.com/index.php?topic=9476.msg215725#msg215725 . has_inactive_mutation would be handy in a few other places, but it's easy enough to recreate if this one isn't workable.

[Gabriel-SE]

What if we automatically set active mutation with power = 0 to active when the player get it ?
So if someone pick Night Vision at chargen, it will automatically be set to active state rather than waiting for the player to press [ and activate it manually.
If this becomes a problem later we can add flag "AUTO_ACTIVE" in mutations.json to check if a mutation should be set to active or not automatically.

[KA101]

Might be workable, will take a look but likely not tonight.

[Snaaty]

+1 for the joke, though

[KA101]

Always time for a classic!Who reference.