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: ++bad argument of :edit does not work properly.
Solution: Return FAIL from get_bad_opt() only when there is no valid
argument. (Dominique Pelle, Christian Brabandt, closes#2966,
closes#2947)
Problem: Largefile test fails on CI, glob test on MS-Windows.
Solution: Remove largefile test from list of all tests. Don't run
Test_glob() on non-unix systems. More cleanup. (Yegappan
Lakshmanan, closes#2354)
