PTXPointReader: fixed a bug, added RGB support.
PTXPointReader: fixed a bug, added RGB support.

kyroskoh/PotreeConverter,Georepublic/PotreeConverter,potree/PotreeConverter,eokeeffe/PotreeConverter,Georepublic/PotreeConverter,eokeeffe/PotreeConverter,potree/PotreeConverter,kyroskoh/PotreeConverter,Georepublic/PotreeConverter,potree/PotreeConverter,sverhoeven/PotreeConverter,Georepublic/PotreeConverter,sverhoeven/PotreeConverter,kyroskoh/PotreeConverter,eokeeffe/PotreeConverter,potree/PotreeConverter,potree/PotreeConverter,potree/PotreeConverter,sverhoeven/PotreeConverter,sverhoeven/PotreeConverter,potree/PotreeConverter,kyroskoh/PotreeConverter