Redact saga-core

It does not compile with clang or against newer boost, and the
project website has been drastically re-organized.

Closes #27111.
python upgrade setuptools to 3.6
python upgrade pip to 1.5.5
pypy upgrade setuptools to 3.6
pypy upgrade pip to 1.5.5
python: update 2.7.6 bottle.
pypy: add 2.2.1 bottle.