Originally reported by: Anonymous

The PEP 0404 discussion was quite controversial.
As a result, we should not refer to a certain Python version that does not exist
(by definition of PEP 0404).
Instead, we will use the name "stackless 2.8".

Revert changes that are not ok, map them to 2.7-slp and only comment on the 2.8 additions, based upon 2.7-slp.

Current approach:

• Stackless 2.8 is based upon Stackless 2.7.X

• it always reflects the latest changes of 2.7.X-slp

• all additions in Stackless 2.8 are Python enhancements back-ported from Python 3.X

• Bitbucket: https://bitbucket.org/stackless-dev/stackless/issue/33