stds-802-16: web site reorganization (internal structure only)

["Roger B. Marks" <marks@boulder.nist.gov>]

I have changed the internal organization of the 802.16 web site. It 
looks the same from a web browser, but there are still some minor 
differences you may notice.

The main change was to rename two directories:

* "coexistence" => "tg2"
* "sub11"       => "tg3"

and move the two TG1 subdirectories into the "tg1" directory:

* "phy" => "tg1/phy"
* "mac" => "tg3/mac"

This will make the structure more consistent and easier to follow. It 
will also make filing easier. This seemed like a relatively easy time 
to make the change.

I have updated all of the links in the HTML files, and I think I've 
also fixed most or all of the links in the PDFs. That's why you won't 
see a difference from  the web.

The only thing I can't fix is the links in the reflector archives and 
in the reflector messages that people have stored away on their own 
computers. Therefore, in order to maintain a legacy of files that 
have been announced to the reflector under the old directory name, I 
have left a copy in a directory with the old name. In a few months, 
I'll just delete these old directories.

Roger