Update randomized format selection
Update randomized format selection

Add Blitz randbats; make No Dmax challenge only.

svivian/Pokemon-Showdown,svivian/Pokemon-Showdown,xfix/Pokemon-Showdown,xfix/Pokemon-Showdown,svivian/Pokemon-Showdown,xfix/Pokemon-Showdown,svivian/Pokemon-Showdown,xfix/Pokemon-Showdown,xfix/Pokemon-Showdown,svivian/Pokemon-Showdown