Adds a new class evolution for Berserker, the Barbarian.

As a Barbarian, the Berserker loses the ability to equip body armor, but gains the ability to wield a two-handed weapon in their off-hand. Additionally, they will unlock Technique/Duelist and Technique/Dual Weapons at 1.0 mastery. Finally, each turn the Barbian attacks a foe, they will automatically eneter a blocking stance to deflect damage with their weapons, potentially setting up deadly counter-strikes.