Add per-role logout URL

Re-rolled the patch so now it applies to dev branch and it seems to be working. When you add the Role timeout, you get the additional option of adding a redirect url at logout. The only problem is, that it can't be empty. If you leave it empty whole site comes crashing down. So it either needs to be a required field or default redirect url needs to be set if the role specific one is not set. So leaving it's status at needs work.

I added the setting to automated tests to get them passing again. I fixed the website errors on empty fields by adding a validation on the setting if it is not empty and if the setting is empty it will take the default redirect URL setting.

Coding standards fixes.

Thanks @benjamincizej for the updated tests and adding a validation. The patch applies and works so marking it as RTBC.