[appserver-io/webserver] Webapp based virtual host configuration

[wick-ed]

It must be possible to deliver a virtual host configuration together with a webapp so the server administrator does not have change the server wide configuration.

UAC:

• Virtual host configuration MUST deployable as part of a webapp
• There MUST be a mechanism to handle configuration collisions (e.g. same hostname/document root/...)
• Configuration MUST be restricted based on the restriction policies for webapp included configuration files