Resistant/Susceptible affect changes

The way that resistances and susceptibilities work on players has been
slightly modified. Previously, there was a hidden cap on how much total
benefit a player could obtain from resistances granted either by equipment or
by spells, after which point there was no additional benefit. Now, as a
player gains a higher resistance rating, they will accumulate an increasingly
small but incremental resistance, with a higher maximum benefit. And the
maximum susceptibility is also being changed in a similar way.

This change was made to give players more viable options to dress for
resistances, and more future opportunities for different types of spelldowns
or equipment downsides based on susceptibility affects.

Thank you to Zistrosk for the efforts in developing and tuning this change.