CWIPC API, memory management, utilities

CWI Point Cloud library - in-core storage of pointclouds, reading/writing, multi-language support (C, C++, Python, C#) Github release of v6.4_stable release on GitLab, for Zenodo archiving. The following repositories belong together, and together form the cwipc software suite:: cwipc 10.5281/zenodo.5779250 cwipc_util 10.5281/zenodo.5779368 cwipc_codec 10.5281/zenodo.5779374 cwipc_kinect 10.5281/zenodo.5779370 cwipc_realsense2 10.5281/zenodo.5779320</p