remove all warning (except one) when compiling with gcc -Wall

VelodyneHDL/Common/Network/vvPacketSender.cxx

VelodyneHDL/Filter/MotionDetector/vtkSphericalMap.cxx

...dyneHDL/IO/GPS-IMU/Applanix/vtkApplanixPositionReader.cxx

...eHDL/IO/GPS-IMU/Velodyne/vtkVelodyneHDLPositionReader.cxx

VelodyneHDL/IO/Lidar/Common/LidarPacketInterpreter.cxx

VelodyneHDL/IO/Lidar/Common/LidarPacketInterpreter.h

VelodyneHDL/IO/Lidar/Common/NetworkSource.h

VelodyneHDL/IO/Lidar/Common/PacketConsumer.cxx

VelodyneHDL/IO/Lidar/Common/PacketReceiver.cxx

VelodyneHDL/IO/Lidar/Velodyne/vtkDataPacket.h

VelodyneHDL/IO/Lidar/Velodyne/vtkRollingDataAccumulator.cxx

VelodyneHDL/IO/Lidar/Velodyne/vtkVelodyneHDLReader.cxx

VelodyneHDL/IO/Lidar/Velodyne/vtkVelodyneHDLStream.cxx

VelodyneHDL/IO/vtkLASFileWriter.cxx

VelodyneHDL/Source/Grid/vtkVelodyneHDLGridSource.cxx

VelodyneHDL/StandAloneTools/PacketFileSender.cxx

VelodyneHDL/Ui/vvCalibrationDialog.ui

VelodyneHDL/Ui/vvCropReturnsDialog.cxx

VelodyneHDL/Ui/vvLaserSelectionDialog.cxx

VelodyneHDL/Ui/vvSelectFramesDialog.cxx