Added spawnmamager functionality.
Spawnmanager acts as a singleton, getting and storing collision objects.
Collision objects collide with the player and are able to cause interactions.
Chickens add themselves to the player's chicken count on hit.
Foxs and cows cause damage (lose chickens).
Player's become invulnerable for a short period on damage taken.
Merge branch 'master' of https://github.com/LiamSauve/CockWrangler