Weapon upgrade system rework

This update introduces a new weapon upgrade system. Until now, upgrading a weapon required an identical copy. That’s no longer the case. Instead, selling weapons now grants components (five different types), which can be used for upgrades. These same components will also be used to upgrade character tiers in future updates.

Other Changes:

• Switch active soldiers during battle – Use keys 1-6 to change your controlled soldier.

• Pause function added – Press Spacebar to pause the game.

• Battle start requirement – You can no longer begin a battle without at least one active soldier.