Faces in plain text files

[Per Starback <starback@ling.uu.se>]

In GNU Emacs 21.2.1 (i386-redhat-linux-gnu, X toolkit, Xaw3d scroll bars),
(but also in in pretest 21.2.92)

	$ emacs -q
	C-x C-f /tmp/newtextfile RET
	T o SPC M-g b b o l d l y M-g d SPC g o . . .
	C-x C-s

This will save a plain text file with the text "To boldly go..."
without ever warning me that the face information won't be saved.

I'm pretty sure many new users who aren't very sure about what can and
can't be in plain text file will expect that the information
that "boldly" should be bold will be in that file somehow.

The M-g functions are in the menus as well, which makes them
especially accessible for new users.

Now users may painstakingly add lots of markup by hand which then is
lost, so this is surely not good.  I don't know what to do about it
though.

* Maybe it would be enough just to not put facemenu functions in the
  menu (except when editing enriched text)?

* Maybe they don't need to be accessible at all except when editing
  enriched text?

* Maybe emacs shouldn't tell you about this until you try to save the
  text, and then tell you that you need enriched text to save that
  information?  (But then it must know what changes are made by hand,
  so this questions isn't triggered by automatic face changes.)