Problem: Tests using term_wait() can still be flaky.
Solution: Increase the wait time when rerunning a test. (James McCoy,
closes#5899) Halve the initial times to make tests run faster
when there is no rerun.
Problem: When evaluating 'statusline' the current window is unknown.
(Daniel Hahler)
Solution: Set "g:actual_curwin" for %{} items. Set "g:statusline_winid"
when evaluationg %!. (closes#4406, closes#3299)
Problem: 'statusline' drops empty group with highlight change.
Solution: Do not drop an empty group if it changes highlighting. (Marius
Gedminas, closes#2228)
Problem: The new regexp engine does not give an error for using a back
reference where it is not allowed. (Dominique Pelle)
Solution: Check the back reference like the old engine. (closes#1774)
Problem: When using try/catch in 'statusline' it is still considered an
error and the status line will be disabled.
Solution: Check did_emsg instead of called_emsg. (haya14busa, closes#729)
