Further down the line, I'm only returning the `Member` on the doLogin, so it's possible for the Handler or Extending Handler to move to a second step.
Also cleaned up some minor typos I ran in to. Nothing major.
This solution works and is manually tested for now. Supports multiple login forms that end up in the correct handler. I haven't gotten past the handler yet, as I've yet to refactor my Yubiauth implementation.
FIX: Corrections to the multi-login-form support.
Importantly, the system provide a URL-space for each handler, e.g.
“Security/login/default” and “Security/login/other”. This is much
cleaner than identifying the active authenticator by a get parameter,
and means that the tabbed interface is only needed on the very first view.
Note that you can test this without a module simply by loading the
default authenticator twice:
SilverStripe\Security\Security:
authenticators:
default: SilverStripe\Security\MemberAuthenticator\Authenticator
other: SilverStripe\Security\MemberAuthenticator\Authenticator
FIX: Refactor delegateToHandler / delegateToHandlers to have less
duplicated code.
Regression introduced through https://github.com/silverstripe/silverstripe-framework/issues/6362.
Quote from the RFC:
```
Thus the order of action precedence becomes
action callback
action on the Form
action on the FormRequestHandler
action on any parent controller (if given)
```
API Add HasRequestHandler interface
API Refactor Link() and url handling behaviour from Controller into RequestHandler
API RequestHandler classes now must define url_segment to have a default Link()
API Clean up redirectBack()
