7045697: JDK7 THIRD PARTY README update

[Kelly O'Hair]

Hopefully Jeff will reply on this.

There are 2 Third Party Readme files, one sits at the top of all the open source repositories
for the open source, the other is placed in the built Oracle JDK images.
There was a great deal of duplication in these files, but one was a closed legal file, and
the other an open one, and managing the contents of these files is not trivial.
Unfortunately it was not possible to do all this work in the open.

As I understood it, there were some minor corrections, but mostly just a cleanup of the existing file.
Nothing earth shaking that I can remember.

-kto