Fix bug in errors module when error index out-of-range, fixes #16
because the seg fault occured due to an out-of-range -1001 error
thrown by the Linux OpenCL ICD loader.
Add friendly error message when no OpenCL platforms are found
Fix unordered teardown when no devices found
Abbreviate error messages for non-debug builds
Add wrapper for the clEnqueueNativeKernel() function, closes #5
Update docs to reflect commit f70849d
i.e. implementation of a wrapper for the clEnqueueNativeKernel()
OpenCL function.
Add test for ccl_kernel_enqueue_native() function

- Test working with Intel and AMD CPU OCL implementations on
Linux.
- Test checks if device has CL_EXEC_NATIVE_KERNEL execution
capability, so it doesn't fail with unsupported devices such as
GPUs.
- Test will not work with OCL stub because clEnqueueNativeKernel()
is not yet implemented in the OCL stub.
Add clEnqueueNativeKernel() to OCL stub

The test for ccl_kernel_enqueue_native() function now works with
the OpenCL stub.
Add basic error checks to clEnqueueNativeKernel() in OCL stub
Remove 'v' prefix from utils version number
Remove unnecessary line of code in OCL stub regarding a
(previously) non-used variable.
Fix minor warning in test_queue when compiling for OpenCL 1.1
Remove device container abstract class methods from public API
Remove abstract wrapper definition and some methods from public API
Update protected CCLMemObj wrapper file/methods
in accordance to latest commits
Set ccl_wrapper_add_info protected+set protect. method docs as internal
Windows: fix warnings when compiling with MinGW 64-bits
Windows: fix native kernel compile with MinGW 32-bits
Minor code improvements
Fix minor warning in test_kernel when compiled for OpenCL 1.0
Add build options for generating internal docs