Merge pull request #8 from mike96/master

Merge day!
Added feature list
Added feature list
Fixed warning
Added new shading type for sprites (NOTEXTURE)
Now sprite batcher support multiple index types (Points, Lines and Triangles)
Added polygon rendering
Added transform state for Vector2<T> for more compact parameters
Fixed SpriteBatcher calling bug
Added PhysicalObject for better control of game scene
Updated math header
Fixed warning
Added physics debug draw for PPoly
Added Enemy class and implemented physics callback function (inside PlayGameState)
Updated feature list
Fixed scale transform state bug
Added circle rendering to SpriteBatcher
Updated feature list
Made joystick always visible
Updated global debug variables