Add a Glasbey color lookup table to pcl_common library
Use color lookup table from pcl_common instead of a local copy
Improve label to color mapping when paint NaNs with black option is enabled
Use Glasbey colors by default in pcl_pcd2png tool
Add getGlasbeyColor() and getRandomColor() functions to colors.h
Add PointCloudColorHandlerLabelField class

This includes both template class and a specialization for
PCLPointCloud2 objects
Add specializations of addPointCloud() and updatePointCloud() for PointXYZL
Add label field color handler in pcl_viewer
Merge pull request #849 from taketwo/add-label-handler

Add a new PointCloudColorHandler for "label" field