* etc/NEWS: In terminal-oriented subshells, the EMACS environment

* etc/NEWS: In terminal-oriented subshells, the EMACS environment
variable now defaults to Emacs's absolute file name, instead of
to "t".
* etc/PROBLEMS: Adjust tcsh advice for this.
* make-dist (EMACS): Exit and fail if the EMACS environment
variable is set to something other than an absolute file name.
* lisp/comint.el (comint-exec-1): Set EMACS to the full name of Emacs,
not to "t".
* lisp/progmodes/compile.el (compilation-start): Likewise.
* lisp/progmodes/idlwave.el (idlwave-rescan-asynchronously):
Don't use expand-file-name on invocation-directory, since this
might mishandle special characters in invocation-directory.
* man/faq.texi (Escape sequences in shell output): EMACS is now set
to Emacs's absolute file name, not to "t".
(^M in the shell buffer): Likewise.
* man/misc.texi (Interactive Shell): Likewise.