IG charter: modification suggestion

Hi Charles, Hi Kaz,

I have reviewed the initial draft charter and wrote out my
modification suggstion.

I modified the inital draft charter directly, for my concern lie
mainly with improving the expression itself in order not to be
misunderstood by people in various industries, especially TV
industries or broadcasters.

I have also merged or reflected ongoing comments and discussions on
the ML in my modified version of the charter.  I know some of them
require additional discussions.  So I just tried to suggest balanced
solutions to them.

I have not touched the section on `Decision Policy', because I did not
follow the discussion yet.  I would like to comment it on the ML later.

# Attached is my modification suggestion.

Regards,
Yosuke