Changes necessary for lccp pull request #718
Fix for Mac OS X

It's the other way around, pkg_check_modules first parameter is the prefix that should be uppercase and the second is the module
CMake pkg_check_modules sets GLEW_INCLUDEDIR

not GLEW_INCLUDE_DIR
PCL formula is in the official homebrew repo

Closes #899
Fix setSize () in PCL visualizer
Merge pull request #920 from fran6co/patch-9

Fix for Mac OS X
Merge pull request #921 from fran6co/patch-10

PCL formula is in the official homebrew repo
Merge pull request #923 from VictorLamoine/master

Fix setSize () in PCL visualizer
Merge pull request #919 from jpapon/supervoxel_impl_to_cpp

Changes necessary for lccp pull request #718
Add Ensenso support in CMake files
Add Ensenso grabber example
Add EnsensoGrabber class
Add Ensenso simple viewer
Add Ensenso documentation & tutorial