output some OpenGL capability constants at initialization.
output some OpenGL capability constants at initialization.

assert OpenGL support at least 16 attribs, to see how many GPU support
this
(OpenGL ES 2.0 spec. only need 8 attribs)

eastcowboy2002/gles-study,eastcowboy2002/gles-study,eastcowboy2002/gles-study,eastcowboy2002/gles-study,eastcowboy2002/gles-study,eastcowboy2002/gles-study