Adding Domain and Path to FormsAuthenticationConfiguration

There is no way to modify the path or domain of the auth cookie.  Now
there is a way to provide the domain and path via the
FormsAuthenticationConfiguration.

2 Additional Tests were created.
fixing minor code style issues
Merge pull request #1000 from adamclerk/FormsAuthConfigCookieDomainAndPath

Adding Domain and Path to FormsAuthenticationConfiguration