Add ReadPixels, DeleteBuffers, GetIntegerv function
Change the parameters of ClearColor to float64

Allow clearcolor accept float64 parameter, so you can clearcolor to
specific color
Add Inverse and Transpose func to the Mat4 obj
Change the method to Mat4 instead of *Mat4
Merge pull request #1 from extrame/master

Add ReadPixels, DeleteBuffers, GetIntegerv function