Users logout action returnpage parameter

In some cases returning to home page is not the best action to propose to users.
This small change allows developer to specify the return page - in similar way as in loginAction..Defaults to home page (as to the moment).

| Q             | A
| ------------ | ---
| Bug fix?      | no
| New feature?  | yes
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | no
| License       | MIT
| Doc PR        | no