If the user explicitly disables the basic security features and forgets to
@EnableWebSecurity, and yet still wants a bean of type
WebSecurityConfigurerAdapter, he is trying to use a custom
security setup and the app would fail in a confusing way without
this change.
Fixes gh-568
Makes them a lot more readable IMO, and also enables @Autowiring
from the context into the test case (sweeet). I added @DirtiesContext
to all of them as well to be on the safe side, but possbly that can be
optimized in some way as well.