Rmk30 another tedit release

[rmkaplan]

This includes updates to all core Tedit files, plus minor updates for compatibility to TMAX and a few other separate applications. This supercedes the draft PR #1673.

What this includes:

• More work on eliminating Xpointers through TEXTOBJ and SELECTION (still a bit more to do).

• Performance improvements in line updating when typing and especially printing (important slow case remains: printing at the end of the stream, e.g. for transcript/dribble applications)

• Fixed glitches in transitions between fat XCCS characters on either side of image objects

• Scrolling improvements
  - Fewer line-update subroutines, for maintainability
  - Better caret placement with keyboard input
  - Better line and caret placement at bottom of pane and end of document, with or without EOL's
  - Fix scrolling TEDIT window when left side off-screen updates incorrectly #1677 (offscreen on left)
  - Better behavior when reshaping

• New functionality
  - meta-d/D brings up DINFO man page, like Sedit, for a selected word (a "word" is an atom according to the reader environment, if seeing a Lisp source file or function) TEDIT: add meta-d for man page, meta-o for ED open #1739
  - meta-o/O opens an Sedit, if possible, for a selected word also TEDIT: add meta-d for man page, meta-o for ED open #1739
  - READONLY property can have value QUIET instead of just T: Still ignores attempted changes but doesn't put up a warning message TEDIT feature: Quiet variant of READONLY #1738. Perhaps useful for applications like hexdump (@pamoroso )
  - New property APPEND: allows updates only at the end of the stream, FWIW.

• Changed behavior:
  - Textstream BOUT now behaves like BOUT (and printing) to other output streams: appends at the end, replaces in the middle. TEDIT BOUT should replace and not insert #1740, also Peculiarities with printing(BOUT) to a Tedit stream #1701.
  - BOUT also doesn't create a history event--not undoable. There is some discussion of this in Peculiarities with printing(BOUT) to a Tedit stream #1701, and this can be adjusted or conditioned on a property. E.g. only make the last 100 BOUT's undoable, like the exec's history list. But BOUTing is really something that programs do, typically not related to user-interface inputs.

(I'm marking this as Draft for now, but please try it. I'll add more comments if I think of more things to mention.)