Allow RP Contribution to become Negative

[Chrism]

I'd like to see RP contribution numbers (for individuals in clans, viewable in the Tops List) able to become negative numbers.

When you're killed in a clan battle and lose RP for the clan, it appears to deduct it from your contribution total, but it stops a 0.

This would still need to decay like RP numbers do now (perhaps based on absolute value?).