Currently system.views stays around even after the last view is dropped. This can result in confusion behavior like the following:

1. Create a collection "stuff" in db "foo".
2. Add a view on "stuff" called "stuffview" (in db "foo").
3. Delete that view and its underlying collection.

OBSERVE: foo.system.views still exists, although it's empty.

4. Try to recreate the collection from step 1 but on db "Foo". (Note the case difference.)

OBSERVE: This fails with DatabaseDifferCase.
EXPECTED: There's no content in db "foo", so it shouldn't prevent our creating db "Foo".