Merge branch 'release-0.43.0' into develop
Added new functions to EXT_direct_state_access
Multiple changes

- Added new functions to PathNV.
- Moved ARB_compatibility enumerations to separate files.
- Updated the CompatibilityMatrixMode enumeration.
- Minor changes in header includes.
- Updated the GLX context wrapper.
- Updated the GLX example harness.
Updated the news feed source
Added a new example
Updated PathNV and PathArrayNV

- Member functions that previously returned void now return *this.
Updates in EGLplus

- Added the GLColorspace enumeration and related surface attribute.
Added partial support for EGL 1.5
Updated the devel/testing implementation of EGL
Updated the build system

- Added support for SDL in the GL version/extension detection module.
Updated the build system

- Added support for GLX in the GL version/extension detection module.
Minor update to the X11/GLX wrapper
Updated the X11/GLX wrapper
Multiple changes in NV_path_rendering

- Moved the enumerations, PathNV and PathArrayNV into separate headers.
- Updated the PathNVColor enumeration values.
- Updated the PathNVCommand enumeration values.
- Added the PathNVSpec class.
- Added PathNV::Spec and PathNV::Dashes.
- Updated the examples using NV_path_rendering.
Multiple changes in NV_path_rendering wrapper

- Documentation update.
- Added PathNV::SubSpec(...).
- Added BriefPathNVSpec<T>.
Minor fix in BriefPathNVSpec
Update of the GLM adaptor

- Fixes #56.
Removed two of the older OGLplus examples
Updated the cloud_trace advanced example
Update of the cloud_trace advanced example