OpenCL::createDevice now probes for platforms for clGetDeviceIDs

My implemenation (windows, AMD APP sdk with ATI radeon) doesn't support NULL (failed with CL_INVALID_PLATFORM) so have to get platform id's to supply as arg.
Also fixed failure not returning 0 as it should.
Merge pull request #1 from SoylentGraham/patch-1

Fixed pointer to source inside std::string
Merge pull request #2 from SoylentGraham/patch-2

build() now automatically adds include path, and build errors are now di...
Merge pull request #3 from SoylentGraham/patch-3

OpenCLKernel::setArg now returns success/failure
Merge pull request #6 from SoylentGraham/master

OpenCL::createDevice now probes for platforms for clGetDeviceIDs