Fixed setCameraPosition in PCLVisualizer.

After setting the new camera position the camera clipping planes
where not adjusted which resulted in a black render window.
The site which pointed me in the right direction was
http://www.vmateevitsi.com/2011/10/25/vtkcamera-problem-with-setposition/
Fixed drawing a cube and a circle with vtk 6.x

It was missing a call to tf->Update() when creating certain shapes.
See this forum post for more information.
http://www.pcl-users.org/Drawing-a-cube-td4034458.html#a4035128
Fixed issue #874 by ensuring that h_index is never negative (which only appears to happen when distance is exactly 0).
Fix compile for CUDA and VTK 6 for gpu_people module.
Merge pull request #873 from dirklanger/master

Fixed drawing a cube and a circle with vtk 6.x
Fix bugs in cone visualization
Merge pull request #876 from yangyanli/fix_vtk6_cuda_compile

Fix compile for CUDA and VTK 6 for gpu_people module.
Added function to set playback speed for OpenNI2 grabber.
This only has an effect on file devices.
Fix bad orientation & origin propreties
Merge pull request #879 from VictorLamoine/ply_fix

[PLYReader] Fix bad orientation & origin propreties
Merge pull request #872 from nylocx/cameraPoseFix

Fixed setCameraPosition in PCLVisualizer.
Merge pull request #881 from taketwo/pr877

Fixes for Cone Visualisation
Merge pull request #882 from nylocx/oni2PlaybackControl

Added function to set playback speed for OpenNI2 grabber.
Fix shapes not drawing with VTK6
Minor tutorial fixes
fixing bug of estimating translation vector
Merge pull request #884 from VictorLamoine/local_doc_tutorial_fixes

Minor tutorial fixes
Merge pull request #883 from VictorLamoine/vtk6_fixes

Fix shapes not being drawn with VTK6
Merge pull request #875 from mohawkjohn/issue_874

Fixed issue #874 by ensuring that h_index is never negative
Merge pull request #885 from tttamaki/master

fixing bug of estimating translation vector