Porting the essential parts of EPAM System's "openvr" branch to the
master branch.
Original authors:
Natalia Smirnova, EPAM Systems, Inc.
Pavel Smirnov, EPAM Systems, Inc.
Original fork:
https://github.com/epam/pymol-open-source/tree/openvr
Adjustments:
- Make feature optional with "--openvr" compile option
- Python 3 support
- Remove C++11 workarounds
- Exclude build system changes
Co-authored-by: Natalia Smirnova <Natalia_Smirnova@epam.com>
Co-authored-by: Pavel Smirnov <pavel_smirnov1@epam.com>
