Style issues and  unbinding texture location.
Output pointer bug, fixed!
Fixed cuda 3 uncompatibility
New CUDA back projector voxel based
New CUDA sart version
Added CudaBackProjectionImageFilter
Added CUDA option
Added CUDA option
Relocation of unbind textures inside CleanUp function
Clamp mode modified
Comments removed
Member functions passed to be virtual
Merge branch 'master' of github.com:SimonRit/RTK
gcc 4.7 compatibility
Merge branch 'master' of github.com:SimonRit/RTK
Fix compatibility when CUDA is not present
Fixed parsing of gcc version
Add rtk::ThreadIdType

Add ThreadIdType in rtk namespace:
  - int for ITK < 4
  - itk::ThreadIdType for ITK >= 4
Remove debug message
Merge branch 'master' of github.com:SimonRit/RTK