Bugfix release:

• [OpenGL] Add support for RG8 textures
  
• [OpenGL] Support nonperspective interpolation on GLES hosts
  
• [OpenGL] Improve support for texture shadow LOD
  
• [Vulkan] enable support for more extensions
  
• [Video] Add support for H264 and H265 video encoding
  
• Enable the use of external objects for AMDGPU based hosts
  
• Fix caching type for llvmpipe based hosts thereby enabling blob resources
  
• Fix a series of errors reported by static analysis and other bugs (see git log)