CAS-1425: aligned view names to match the jsp filename

Some view names in default_views.properties have been updated to match the file names of the jsp's. The respective view names in the login-webflow.xml have been updated as well. This pull fixes https://github.com/Jasig/cas/issues/490
No, a disabled service is `registeredService.isEnabled()`. Non-existing services are not allowed to use CAS anyways. The most interesting aspect of this pull is the ability to decorate the login page and I would like to stick to this. Not much else is going to be customized, but we can certainly track what you're describing in a separate issue.