Version 0.66 - Backfixes, chest upgrades

[h3]Version 0.66 - Backfixes, chest upgrades[/h3]

• Added the ability to upgrade the chests! Upgraded chests will start opening silver cards immediately.
  
• You can now keep artifact progress in the forge when restarting the guild (for crystals). We will soon add artifact saving at every 3rd level.
  
• Tweaked the balance of some guilds.
  
• Bugfixes!