Panel suggestions

[jordwalke]

I had some suggestions about the panel. I left them inline here:
(Option to use status bar instead, doesn't come up until reentering the line, and doesn't go away when fixing the error).

c2f3e22#diff-7eed4e10e38b4d6193dc92fce69dfaaeL420

[cynddl]

To recap the discussion: the panel may be intrusive, but necessary to read all the error messages.

It's not difficult to add a setting in order to opt-out of the panel and only display errors in the status bar. I think it may be a good solution for some people.

[jordwalke]

I also played around with having the panel be one line high (and converting newlines to spaces in the output), and it's virtually the same as having the status bar display messages.