Everything Is Fine update

Updated my GDU GameJam entry to fix some bugs:

• health can no longer go below zero
• player safe zone removed from top of screen

Also made some game play changes to make it more fun and challenging:

• food items can now also spawn in the heart locations
• hearts have a 10% chance of spawning, so be careful!
• score is now based on how many food items you pick up, so now you have a reason to move around!
• being hit by people will cause 10 stress, hit by car is now 20 stress
• added two more people spawn points