GPUArrray --> GPUArray

Fixed a confusing typo in the docs, where the class name "GPUArrray" was spelled incorrectly.

Add access to cuda context handle

Update  compiler.py

Solves error generated by using sys.maxint constant in Python 3.1.5^, sys.maxsize is available for use in Python 2.0.0.

Python docs for reference:
- sys.maxint deprecated in Python 3.1.5^: https://docs.python.org/3.1/whatsnew/3.0.html#integers
- sys.maxsize supported in Python 2.6^ : https://docs.python.org/2.6/library/sys.html#sys.maxsize

Ensure the views from DeviceAllocation.as_buffer are writeable.

Surf an dtex extensions

Adding complements to use Texture and Surfaces 2D Layered