Fix COMMENTCOLUMN to print edited date on one line

[masinter]

Do you know what controls the comment starting column and the maximum line length, and can they be adjusted slightly such that it doesn't end up splitting these comments over two lines instead of keeping them on one?

Originally posted by @nbriggs in https://github.com/Interlisp/medley/pull/553#discussion_r737810200

@rmkaplan

There’s a variable COMMENTLINELENGTH = (116 . 126), maybe that has something to do with it

[masinter]

looking at this: there seem to be several problems.

• EDITDATE? doesn't seem to recognize old-style edit dates (* bvm%: "26-Mar-86 14:03").
• There doesn't seem to be COMMENTLINELENGTH... instead there's a COMMENTCOLUMN which is a CONS of to FLOATPs (0.6 . 0.1) which seems to only be used by SUPERPRINT/COMMENT1 and only the .6 value
• When going out to a file, it switches to COMMENTFONT and back again, causing extraneous font control character shifts (?)

The code has been subject of multiple incomplete patches, unfortunately. It's working on character POSITIONs but guessing that AVERAGEFNLENGTH is 5 and not taking into account variable width fonts.

SEDIT has its own heuristics and prettyprinting methods which seem to be more stable.