Move under FirefoxGraphics org

[kvark]

This is a great project, I find it useful to navigate Firefox code.
Would be nice to see it under https://github.com/FirefoxGraphics

[sotaroikeda]

It is OK for me. But there is one concern about it. Diagrams are drawn by using Visio Professional. Then the diagrams might not be modified by other guys.
@jrmuizel, how do you think about it?

Majority of diagrams are a bit obsoleted. I am thinking to update them.

[jrmuizel]

I don't feel strongly either way.