desupporting X10 and old X11 releases (was: Re: isearch multiple buffers)

[Dan Nicolaescu]

Richard Stallman <address@hidden> writes:

  >     X10  (window-system-version mentions it, is it still supported?)
  > 
  > I think all code specific to X10 was all deleted ages ago.

There's still a bit of code in the s/* m/* files and Makefile.in that
deals with LIBX10_SYSTEM and LIBX10_MACHINE.
Hopefully most of it will disappear after we desupport some platforms.

But there's also oldXMenu/X10.h. Is that still relevant? 
Is oldXMenu still used?

  > There are a few conditionals that test HAVE_X11, but they really
  > use it to test whether X is present at all.
  > 
  > There are still conditionals for X11R3 (testing HAVE_X11R4).  That
  > must be long obsolete.  We can delete them if that would save us any
  > trouble.

It will allow us to get rid of some code in xterm.[ch] and xfns.c, so
it seems worth doing.

How about X11R4, is that still worth supporting? 

  > Your list of platforms to propose to delete seems like a good start.
  > Please collect others' suggestions, then post the final list in a few
  > days.

Sounds good.