Currently if a web app is deployed only to a specific virtual server, the launch
link for that web app still uses the DAS in forming the launch link for PE.
The current semantic for VS in deployment is such that if no virtual server is
specified, then it means the deployment applies to ALL VS.
If VS is specified, it will only deploy to the specified VS.
So, if you create a VS, and then deploy only to this new VS, the launch link
still uses the host name in forming the URL, thus, it won't work. user gets a
Besides fixing the launch link, we should also show the VS in the application
edit screen for PE. otherwise, user has no idea which VS this app is deployed to.