Spooky Heroes updated

Hi all,

Following player suggestions, a few things have been changed in the game :

- A key binding help has been added in the pause menu (Press Esc or Start)
- The camera is no longer locked when a rift spawns. However the bounty earned when destroying one should still be an incentive to actively focus on them.
- When dying against a boss, the player now respawns near its lair in easy and normal modes.

Those changes should make the game less of a hassle for new players and remove the camera problem with rifts.

I'm also aware of some problem with the Linux release, some backgrounds not showing or some black screen problem occurring. If such things happen to you, please, contact me with your configuration so I can correct that asap.

Thanks for your time !