Merge branch 'release-0.49.0' into develop
Updated the news feed source
Added syntax sugar operators for Sampler
Documentation update
Multiple changes

- Moved the MissingFunction class into a separate file.
- Documentation update.
Multiple changes

- Added constructors to CStrCRef.
- Documentation update.
String-related updates

- Replaced all occurences of StrLit with StrCRef.
- Removed the StrLit type.
Fixed minor problem in standalone example.
Documentation update
Program variable-related changes

- Added FragData - a wrapper for fragment data outputs.
- Minor changes in the ProgVar implementation.
- Removed the Set functions from UniformBlock.
Multiple changes

- Documentation update.
- Update in the implementation of vector.
Multiple changes

- Documentation update.
- Updated the implementation of Vector.
Documentation update
Documentation update
Documentation update
Documentation update
Multiple changes

- Documentation update.
- Minor changes in Vector, renamed MultiplyBy to Multiply and
  DivideBy to Divide.
Fixed a problem in the cell image generator
Multiple changes

- Documentation update.
- Added scripts for generating enum quickbook documentation files.
Multiple changes

- Minor change in oglplus::Error.
- Documentation updates.