This makes gen 7 the default mod, updates the tests to match, and fixes
the corresponding build error.
Note that this only changes the default Tools mod, the default Formats
mod is now gen6. gen7 must be specified by name in a format, for that
format to be a gen 7 format.
Previously moves like Leech Seed incremented residualdmg when used by 1,
but this doesn't actually happen in the game. Instead, an actual game
uses a flag to store toxic poisoning flag, and when it's not specified,
these statuses always dealt 1/16 of full HP.
This fixes the issue where the sequence of moves (Toxic followed by Leech
Seed) was dealing 1/16, 3/16, and 4/16 of full HP in residual damage,
instead of 1/16, 2/16, and 3/16.
