1.2.0.a -> 1.3.0.a

Tower now correctly takes damage and can die

Game Overs (Light Blue Squares) now spawn at the left side of the world

Zombie Spawners (Red Squares) now spawn at the right side of the world

Added a player health bar

Update to version numbers for1.3 and after

Major.Minor.Small.Invisible  -> Major.Small.Minor.Invisible.

ie. Next update will be 1.3.1.a, not 1.4.0.a.

You don't care but I do.