v1.9.2

Note: the packages generated by github (Source code links) do not contain the submodules. Use geogram-1.9.2.tar.gz or geogram-1.9.2.zip instead to get everything.

What's changed

• multi-GPU support in OpenNL
• String::format_time() to display time in hh:mm:ss format
• CmdLine::load_config() and save_config() to load/save command line arguments from file
• small bugfixes

Full Changelog: v1.9.1...v1.9.2