Added Health Bars

Health bars for each hero. The code is a little clunky, and the bars
take up a lot of the screen. I made the bars slightly transparent.
Merge pull request #5 from Lakon/development

Development
Merge pull request #20 from Lakon/development

Added Health Bars
Merge pull request #6 from MikePaNtZ/development

Development
Added bullet deflection by shield

The bullets from enemies are too fast and too powerful. We need a
defense against them. Enter the shield!
Merge pull request #21 from Daikatana/master

Shield deflection
Merge pull request #15 from Daikatana/master

Added shield deflection
Merge pull request #14 from MikePaNtZ/development

Development merge
Map Wrapper and Groundwork for Navigation Mesh

I wrapped up the map stuff in a class called Map. I'm also planning on
creating a navmesh for the maps, so that we can get the ai moving in a
sane way. I added the classes (e.g. Graph) needed for that.
Merge pull request #22 from Lakon/development

Development
Moved Hud to its own class

Created a Hud class that handles all the hud stuff. Makes PlatformerGame
a little cleaner.
Merge pull request #23 from Lakon/development

Moved Hud to its own class
Added HeroGun Subclasses

HeroGun Subclasses added to change each hero's bullet image. Health bar
now red too.
Merge pull request #24 from Daikatana/master

Added HeroGun Subclasses
Merge pull request #16 from MikePaNtZ/development

Development merge
Added flicker tint

I just added something similar to powerUp colors index, except using a
transparent color. No need for spriteFlickerAnimation. The isHit color
index is part of the GameCharacter class and the Hero class references
it. We could change the timing of the flicker.
Merge pull request #25 from Daikatana/master

Added flicker tint
Fixed bullet deflection.
Merge pull request #26 from Daikatana/master

Fixed bullet deflection.
First Version of Nav Mesh

Got the first version of the nav mesh working by creating a graph of
walkable tiles.. I added a debug drawer class to the project so I can
draw the mesh to the screen. Looks real pretty lol. Currently its very
inefficient, because it connects every node with every node in a 5 tile
radius and probably duplicates most of the edges. Also it takes 5 sec
longer to start game.