WIP: Fix sequence for Scala 2.11.x.

Beginnings of a workaround ... this will need arity-specific cases for Apply2 similar to those for Unapply. Maybe Unapply can be reworked to accommodate this scenario better? I expect something similar will work for traverse.

Removed UnapplyAux since it appears to be irretrievably broken with Scala 2.11.x.