Deprecates the support of old D3D9-and-10-level GPUs

[gongminmin]

Focus on newer platforms.

• No D3D11 feature level 9 and 10.
• No OpenGL 2 and 3, must have DSA.
• No OpenGLES 2.

[gongminmin]

Divide into 2 steps to make this move a little smoother. In v4.10, the requirements are:

• For deferred rendering framework
  • Shader model 4+ (D3D 10 +, OpenGL 3+, OpenGLES 3+)
  • MRT > 2
  • Float texture read/write
  • etc
• For others
  • D3D 9.3+
  • OpenGL 3.1+
  • OpenGLES 2.0+

A typical lowest-end GPU would be Intel HD 3000.