PCL 1.6 Support and Examples

Updated for PCL 1.6 support
========

Edited original ofxPCL by satoruhiga to support the latest PCL.


PCL Examples
========

Now ported 5 examples from pointcloud.org examples:

* ofxPCLExtractIndices
* ofxPCLGreedyProjection
* ofxPCLResampling
* ofxPCLStatisticalRemoval
* ofxPCLVoxelGrid

Be careful that these examples requires either <http://svn.pointclouds.org/data/tutorials/table_scene_lms400.pcd> or <https://code.ros.org/trac/ros-pkg/export/34074/stacks/point_cloud_perception/trunk/pcl/test/bun0.pcd> to be placed under `<build_directory>/share/openframeworks`. Also see issues for linking errors.

Finally, these examples have different `CMakeLists.txt` to other examples since other `CMakeLists.txt` didn't work for my environment.