[Python-3000] Python 3.0a2 release

["Martin v. Löwis"]

> I've modified the PGO builds and the build_pgo batch file I copied from
> the PCbuild8 directory. For AMD64 builds we either have to buy you an
> AMD64 processor or somebody else has to run the PGI and PGO builds.

So what's the build process? Is it

1. start a VS build environment shell
2. cd to PCbuild9
3. run "build_pgo"

Any additional steps? Should I pass arguments? Can you kindly document
it in readme.txt?

Regards,
Martin