Display target url - login.jsp

[Rod Widdowson]

> You can also use the idpui stuff which I have not converted over to using
> just yet.. but that should be another way to get the entityId / RPid. 

For completeness:  what this does is make an attempt and rendering something
sensible to an end user.

So <idpui:serviceName/> will return the first it finds in this list:
- Either what the metadata has (which can be localized), 
- The DNS name stripped from the entityID if it is in URL format.
- The entity name

(https://wiki.shibboleth.net/confluence/display/SHIB2/IdPAuthUserPassLoginPa
ge#IdPAuthUserPassLoginPage-ServiceProviderName)

This is aimed at being user info - not for making decisions on what to
display.  For that I would recommend what Peter said - separate entityIds.