Misago single signon support

[sirex]

Add possibility to sign in using OAuth/OpenID, because Misago does not support this.

See: rafalp/Misago#415

[narun4sk]

What is the benefit of OAuth/OpenID? Why we want this?

[sirex]

For many reasons:

• For convenience, you can register to forum with single button click.
• For security, because we will not have to store user passwords.
• For protection from spammers and bots, because we can use white-list of supported OAuth/OpendID priveders.

[narun4sk]

I'm frankly don't know anyone of my friends using OAuth/OpendID...
I think it's rather more important to integrate FB, Linked in and similar facilities...

[sirex]

FB, LinkedIn and others, all use either OAuth or OpenID. OAuth/OpentID is the protocol they use.

Probably we will use something like django-allauth where everything is integrated in one place.

[narun4sk]

OK, got it.