Allow Edebug's instrumentation to be used for other purposes

Allow Edebug's instrumentation to be used for other purposes

* lisp/emacs-lisp/edebug.el:
(edebug-after-instrumentation-functions)
(edebug-new-definition-functions): New hook variables.
(edebug-behavior-alist): New variable.
(edebug-read-and-maybe-wrap-form): Run a hook after a form is
wrapped.
(edebug-make-form-wrapper): Run a hook after a definition is
wrapped. Remove message for each definition.
(edebug-announce-definition): New function.
(edebug-enter): Rewritten to change behavior of Edebug based
on symbol property `edebug-behavior' and `edebug-behavior-alist'.
(edebug-default-enter): New function which does what `edebug-enter'
used to do.
(edebug-run-slow, edebug-run-fast): Modify edebug-behavior-alist.
(edebug-before, edebug-after): Function definitions are now set by
`edebug-enter'.