In lisp-mode, "labels" and "flet" are not highlighted while stuff like
"letrec" and "save-excursion" are (wrongly) highlighted.  To see that,
open a file with name "foo.lisp" and insert something like:

 (labels ((foo ())) (letrec ((bar bar))))

I think that the patch below would fix this problem. The patch also
removes "featurep" because that's not a defined operator in Common Lisp.
I can also write a ERT test if needed.

In GNU Emacs 24.3.50.4 (i686-pc-linux-gnu, GTK+ Version 2.24.10)
 of 2013-10-19 on ix
Bzr revision: 114715 rgm@gnu.org-20131019023520-s8mwtib7xcx9e05w