Small Demo Update

Small update for the Back To The Dark demo:

• Added a down portal within the second level for endless runs.
  
• Reduced bow and staff charge time.
  
• Added fireball charging glow.
  
• New help pages to enlighten the journey.
• Gamepad options for auto-aim and auto-fire.
• Option for Pause On Inventory. Defaults to On. Disable for the true dungeon experience...
• Pause menu now, err, pauses.
• Fixes and tweaks for loot rarity...
  
• Fixed wrong avatar icon.