Set up Tile Engine and Tiles

-Added:
  -TileEngine.cs
  -Tile.cs

-Added a "FeetLoc" property to LevelObject.cs that returns a Rectangle
-Reorganized the source files a bit by adding a Collision folder and putting Collideable.cs, Hitbox.cs, and Hurtbox.cs inside it
Finished setting up Tile Engine and Tile Types

-Added tile types: None, Block, NoNpc, Warp
-Added TouchesTile and DamagedObject methods in Collideable.cs
-Made all implemented interface methods virtual in BaseLevel.cs so they can be overridden
-Added Debug command for displaying the tiles (Shift + T) and their tile types
Added Support for Mouse and Touch Input

-Added methods to Input.cs
-Added methods to MenuScreen to allow mouse and touch interaction with menu items
-Touch does not yet work perfectly because of the high resolution on the Surface Pro 3. Will need to set the resolution of the game before we can properly test touch
-Touch currently only supports the Tap gesture
Merge remote-tracking branch 'origin/MouseInput' into SetUpTileEngine

Conflicts:
	Top Down Shooter/Top Down Shooter/Debug.cs
Merge branch 'SetUpTileEngine'