Allow the caching behaviour to be controlled globally.

The kernel compilation cache can be disabled by exporting
$PYCUDA_DISABLE_CACHE and the default cache directory can be
overridden by exporting $PYCUDA_CACHE_DIR.

Zero-initialize all fields of Memcpy*D

Some fields were left uninitialized, which doesn't seem very Pythonic.
The CUDA_MEMCPY3D structure is now value-initialized, which ensures all
its members are zero.

Add ability to get handle to CUDA Arrays

Added function to create CUDA Arrays directly from GPUArrays

Just to complete, added function to create CUDA Arrays directly from GPUArrays, maybe in future Texturea Objects and Surfeces Objects could be supported ..

extFPTextureSurfaces

Implemented function to make Cuda Arrays from numpy 2D or 3D array including complex and double support

Improve error handling of non-array types in ArgumentHandler

Ensure the test actually corresponds to the cuda code.

Add support for passing shapes that are ndarrays to GPUArray constructor

Add ability to set real and imaginary components of complex numbers

Add a GPUArray.squeeze() method.