Add support to change openid.svg

[grizzly-monkey]

Like change the name to company SSO would be great to have configurable svg /ico for company sso.

[MatteoJoliveau]

I second this, or at least change the label to "Log in with SSO" or something like that

[tjuerge]

I second this, or at least change the label to "Log in with SSO" or something like that

Something like this? ;-)