http://pylons-webframework.readthedocs.org/en/latest/upgrading.html
This requires several code changes:
* pylons `config` option must be explicitly passed during setup
* the pylons global has been renamed from `g` to `app_globals`
* the pylons global has been renamed from `c` to `tmpl_context`
* set pylons.strict_tmpl_context = False (instead of pylons.strict_c)
* redirect_to() has been swapped for redirect()
* must implement `ErrorDocuments` middleware ourselves
pylons 1.0 also required an upgrade of routes from 1.11 to 1.12. This
required the following changes:
* set Mapper.minimization = True (the default value changed)
* set Mapper.explicit = False (the default value changed)
