Added functionality for loading a 2d texture
	Solution:
	-Addition:
		New class Static2dAsset.

	Placeholder.hlsl:
	-Addition:
		PointSamplerState for pixel shader.
		2DTexture for pixel shader.

	AssetManager:
	-Addition:
		LoadStatic2dAsset function.

	Graphics:
	-Addition:
		LoadStatic2dAsset function.
		Changed wchar_t* fileName to const wchar_t* in
		 LoadTextureFromFile.

	PlayState:
	-Addition:
		AssetID mTest2dTexture.