This changes Ex mode (Q, -e) to work like Vim's "improved Ex mode"
(gQ, -E). That brings some small behavior differences, but should not
impact most Ex scripts (unless, for example, they depend on mappings
being disabled--but that can be solved for -e by skipping user config).
Before this change:
* the screen test hangs.
After this change:
* Q acts like gQ.
* -e/-es differs from -E/-Es only in its treatment of stdin.
This moves towards potentially removing getexmodeline().
(HINT: That does NOT mean "removing Ex mode", it means removing the
Vi-compatible Ex mode, which differs from Vim's "improved Ex mode" only
in some minor details (e.g. mappings are disabled).)
ref #1089 :-)~
9c2099d585