Modified AuthTests to support a derived test class repeating all the tests except running with a virtual directory setup.
Modified existing tests to ensure coverage of both root and virtual directory cases. This commit replicates the login redirect uri issue within the 'Html_clients_receive_secured_url_attempt_in_login_page_redirect_query_string' test.
Fixed the login redirect to not repeat the virtual directory name.
Fixed derived class tests failing when ran together with the base class.
Merge pull request #842 from Its-Tyson/auth-redirect-virtual-directory-issue

Auth redirect virtual directory issue
Merge branch 'v3-fixes' into v3
Merge branch 'v3' of https://github.com/ServiceStack/ServiceStack into v3