float4_ drawing problem
OpenGL uses homigenous coordinates
new default step width
using swizzling operators
Merge pull request #254 from f-koehler/nbody

Nbody example improved
Add opencl_test example

This adds a new example which prints out the OpenCL platforms
and devices found on the system using the OpenCL API directly.
Fix bug when calling reduce() with empty ranges
Merge pull request #255 from kylelutz/opencl-test

Add opencl_test example
Merge pull request #256 from kylelutz/fix-reduce-empty-range

Fix bug when calling reduce() with empty ranges