Flask-sso

- Login error handler can be added to SSO and will be called with
required attributes are missing. If login error callback is set
no `SSOAttributeError` will be raised and application can
return custom error response based on missing attributes.

- The Flask-SSO extension is now released under more permissive
Revised BSD License. (6)
- For testing execute run-tests.sh instead of sourcing it. (4)
- New minimal application example. (8)
- New Tox support for Python-3.4. (4)

- Allowing ';' separator in HTTP data.
- Fix for dictionary key order in tests.
- Fix for Python 3.3 string comparison.
- New dependency: Blinker.
- Code coverage improved to 100%.
- New configuration option SSO_LOGIN_ENDPOINT.

- Initial public release.