Added larger robo battler sizes

There are now three sizes to choose from
robo_battler[anim] -> 40 pixels per frame
robo_battler2[anim] -> 50 pixels per frame
robo_battler3[anim] -> 45 pixels per frame

Please choose whichever your prefer.  To switch between battlers, you
need to change the <Battler Name> in the actor tab of the database, and
you'll need to change the name of the file at the beginning of the VE
Side Battle script.