Incidentally, use the better name, "this.requestUrl", for that variable in
the ShareRoomModel tests.
Consolidate default password-protected parse handling, to simplify
FileModel and FolderModel.
Test proper handling of FileModel and FolderModel content fetching from the
server, including unrestricted and password-protected cases.
Refactor new File and FolderModel tests so that the fetching tests don't
depend on the instantiation tests being run.

In the process, discover ways that the fetching tests were giving
unsubstantiated positives, because they depended on results from the
instantiation tests!  (The extra time to untangle the interdependencies was
worth it!)
Merge pull request #303 from SpiderOak/issue-302-more-content-tests

Issue 302 more content tests