Bug Fixes and Enhancements

### 2.6.13 Bug Fixes and Enhancements

- Light source enhancements
- Fixed normal average, reflection and other related problems
- Fixed cylinder camera problems
- Fixed the use of multiple closed bezier-splines in prism
- Fixed infinite cone bug
- Fixed the use of two subsequent colors, not separated by a comma in checker, hexagon and bricks.
- Fixed gamma correct bugs
- Numerous other bug fixes and optimizations