Checked on AMD OpenCL devices
Changed OpenCL extension

Changed #pragma OPENCL EXTENSION all : enable to #pragma OPENCL EXTENSION cl_khr_fp64 : enable
CUDA will not be present in AMD devices

If CUDA is not present, (which will not in AMD devices) cannot be imported. If not present, return.
Checked on NVIDIA Card
Update execu.py

A new option is added to PyCUDA so that dynamic parallelism can take place. Previously, there used to be a problem with linking options being used as a compiler options. This is removed by adding the new linker option. *Still testing*
Added for
added for capability
Merge pull request #15 from adityaatluri/master

Final Update