ERT should/should-not simple fixes

[Nic Ferrier]

I've suggested this fix a couple of times.

There is currently a bug (perhaps a feature) in 24.3 with the should and
should-not macros. This patch "fixes" it:

--- 
/home/nferrier/emacs-local-20130401/share/emacs/24.3/lisp/emacs-lisp/ert.el.gz.~1~
+++ 
/home/nferrier/emacs-local-20130401/share/emacs/24.3/lisp/emacs-lisp/ert.el.gz
@@ -464,6 +464,7 @@
   "Evaluate FORM.  If it returns nil, abort the current test as failed.
 
 Returns the value of FORM."
+  (declare (debug (form)))
   (ert--expand-should `(should ,form) form
                       (lambda (inner-form form-description-form value-var)
                         `(unless ,inner-form
@@ -473,6 +474,7 @@
   "Evaluate FORM.  If it returns non-nil, abort the current test as failed.
 
 Returns nil."
+  (declare (debug (form)))
   (ert--expand-should `(should-not ,form) form
                       (lambda (inner-form form-description-form value-var)
                         `(unless (not ,inner-form)