[foreign] RFR: Update (Windows) build docs

[Jorn Vernee]

Hi,

I've taken a second pass over the build documentation. I have now:

- Added Windows instructions for Tensorflow.
- Simplified some of the Windows commands by taking advantage of 
--infer-rpath
- Updated the OpenGL example to take advantage of static forwarders.
- Miscellaneous fixes & simplifications here and there.

Please review the changes.

Webrev: 
http://cr.openjdk.java.net/~jvernee/panama/webrevs/updateddocs/webrev.00/

Thanks,
Jorn