Added models for player, zombie, checkpoint, obstacle, and item
added longitude and latitude properties to checkpoint and specialized init
Merge branch 'master' into Models
merged in map kit framework from master
defined and declared properties and inits for player
Added properties, convenience init, and random exercise setter to Obstacle
Added properties, init, and weighted random effect selection to Item
Added properties and convenience init for Zombie
Merge branch 'master' into viewControllers