[x] rock for New Moon, similar to heat rock, damp rock etc.

Issue #848 resolved
J created an issue

exactly what the title says. (as a reminder of what the rocks do: turn their respective weather effect from a five turn weather effect to an eight turn effect, so a rain dance with damp rock would last eight turns)

would really like it for my delta roserade, so I could theoretically pass it off to other pokemon like mega shiftry