Low Entropy

• issues fixed: #224, #277, #288, #290, #291, #292, #293, #294, #295, #296, #297, #299, #302, #318, #319, #324, #325, #329
• Additional fixes:
  • fixed a segfault in PCLVisualizer::addPointCloudNormals
  • fixed PCLVisualizer hanging on 'q' press
  • fixed a bug in MLS
  • fixed a bug in test_io
  • fixed a bug in PointCloudColorHandlerGenericField
  • fixed a bug when writing chars to ASCII .PCD files
  • fixed several errors "writing new classes" tutorial
  • added missing parameter setter in the "concave hull" tutorial