Make more parts of Emacs use new Eldoc capabilities

Make more parts of Emacs use new Eldoc capabilities

Elisp-mode was doing a lot of work that can now be delegated to Eldoc.
Flymake uses the new Eldoc functionality, too, installing a global
documentation function that may report on diagnostics under point.

CEDET's grammar.el was left as the only user of an Eldoc-internal
function.  That function was moved to grammar.el.  That file is still,
somewhat reprehensibly, using an internal function of elisp-mode.el,
but this was left unchanged.

In other situations, eldoc-documentation-functions is used or
recommended.

The only other places where the obsolete eldoc-documentation-function
is still used is in libraries which are presumably meant to remain
compatible with previous Emacs versions.

* lisp/progmodes/elisp-mode.el (elisp-eldoc-funcall)
(elisp-eldoc-var-docstring): New functions.
(emacs-lisp-mode): Put two elements in
eldoc-documentation-functions.

* lisp/emacs-lisp/eldoc.el (eldoc--eval-expression-setup): Setup
new Elisp eldoc-documentation-functions.

* lisp/progmodes/flymake.el (flymake-mode): Use
flymake-eldoc-function.
(flymake-eldoc-function): New function.
(Package-Requires): Require eldoc 1.1.0

* lisp/descr-text.el (describe-char-eldoc): Recommend
eldoc-documentation-functions.

* lisp/progmodes/cfengine.el (cfengine3-documentation-function):
Recommend eldoc-documentation-functions

* lisp/progmodes/octave.el (inferior-octave-mode): Use
eldoc-documentation-functions.

* lisp/cedet/semantic/grammar.el (semantic--docstring-format-sym-doc):
New function.
(semantic-grammar-eldoc-get-macro-docstring): Adjust.