Need equivalent to glDebugMessageInsert

[ghost]

I'm not sure if such a feature already exists, but I want to be able to add custom debug message strings in the GL command log. Basically a console.log on the window.spector API.

This would also be needed for #170

(This is a duplicate of #154 which I only found after creating the issue; however, the original request still stands; it's impossible to have an debug mark / custom message, without also invoking some WebGL call)

[sebavan]

See discussion on #170