Add PyErr_SetFromErrno()
EnvironmentError.__str__
Fix some list behavior and add list.__ne__
Add a flag for self-hosting some of our build scripts

Ie run lint.py tester.py under Pyston, and use Pyston on the setup.py
script to build our test extension modules.

Pass SELF_HOST=1 to make to invoke this behavior
Add sys.exc_info()
Fixes to get self-hosting working
Merge branch 'selfhost'