Problem:    Check for features implemented with "if".
Solution:   Use the Check commands. (Ken Takata, closes #7383)

Problem:    Various inconsistencies in test files.
Solution:   Add modelines where they were missing.  Use Check commands instead
            of silently skipping over tests.  Adjust indents and comments.
            (Ken Takata, closes #6695)

Problem:    More functions can be used as a method.
Solution:   Allow more functions to be used as a method.

Problem:    Some eval functionality is not covered by tests.
Solution:   Add a few more test cases. (Masato Nishihata, closes #4374)

Problem:    Not all windows commands are tested.
Solution:   Add more tests for windows commands. (Dominique Pelle,
            closes #1575) Run test_autocmd separately, it interferes with
            other tests.  Fix tests that depended on side effects.

Problem:    delete(x, 'rf') fails if a directory is empty. (Lcd)
Solution:   Ignore not finding matches in an empty directory.

Problem:    delete() does not work well with symbolic links.
Solution:   Recognize symbolik links.

Problem:    Vim can create a directory but not delete it.
Solution:   Add an argument to delete() to make it possible to delete a
            directory, also recursively.