OpenID: add 'auto logout' option.

That is, make it possible to automatically logout after sending OpenID
response.
OpenID: always enable auto-logout for SSL cert auth.
improved dev lists view

Improved lists view by replacing class-based view to a more
flexible view suggested by tampakrap and mgorny.
Add ability to get ldap user from settings.DIRECTORY or another one

An example could be a temporarily one, or self.ldapobject.directory
Anon user can not have is_verified attr, enable it only for real users
various minor fixes in login tests
Add support for secondary password

Using OkupyCipher I generate a new random secondary password and I add it to
the session. This feature improves user experience and prevents user
from submitting password all time.
Tests for secondary password
Handle unknown hashes in secondary-pass code gracefully.
Add tests for not removing unknown hashes in secondary password
add per-view caching on lists

Added a per-view caching to lists which reliefs server
from HTTP requests and improves performance.
Use bind_as() to localize LDAP identity changes.

Mangling settings globally means that functions running in parallel will
be affected. Instead, use the newly-added bind_as() method to locally
change LDAP identity.
Replace get_ldap_connection with LDAPUser
Remove get_ldap_connection completely
Merge pull request #64 from tampakrap/sec_pass_v5

Secondary password
Merge pull request #61 from mgorny/openid-auto-logout

OpenID auto logout
Fix handling timedeltas in use_nonce().
OpenID: make nonce creation atomic.

get_or_create() is pointless, non-atomic thing. Instead, just try to
create the nonce and catch IntegrityError.
Add tests for *OpenIDStore.use_nonce().
Add uniqueness contraints to enforce one *OTP device per user.