Fix use of paredit-space-for-delimiter-predicates; fixes greghendershott#736

All along we had been using `add-hook` to update paredit's
paredit-space-for-delimiter-predicates.

Commit 3a9675d started supply `t` for the optional LOCAL argument to
add-hook, which is the correct way set a local value for hook
variables.

The problem is, paredit-space-for-delimiter-predicates was never a
hook variable -- paredit doesn't use it via some run-hook variant, and
so it chokes on the `t` value.

Instead just setq-local it in each of our major modes, which should be
fine because they are major modes.

Author: greghendershott

racket-hash-lang.el

@@ -263,9 +263,8 @@ A discussion of the information provided by a Racket language:
   (setq-local completion-at-point-functions nil) ;rely on racket-xp-mode
   (setq racket-submodules-at-point-function nil) ;might change in on-new-lang
   (when (boundp 'paredit-space-for-delimiter-predicates)
-    (add-hook 'paredit-space-for-delimiter-predicates
-              #'racket--paredit-space-for-delimiter-predicate
-              nil t))
+    (setq-local paredit-space-for-delimiter-predicates
+                (list #'racket--paredit-space-for-delimiter-predicate)))
   ;; Create back end hash-lang object.
   ;;
   ;; On the one hand, `racket--cmd/await' would be simpler to use

racket-mode.el

@@ -202,9 +202,8 @@
             nil t)
   (setq racket-submodules-at-point-function #'racket-submodules-at-point-text-sexp)
   (when (boundp 'paredit-space-for-delimiter-predicates)
-    (add-hook 'paredit-space-for-delimiter-predicates
-              #'racket--paredit-space-for-delimiter-predicate
-              nil t)))
+    (setq-local paredit-space-for-delimiter-predicates
+                (list #'racket--paredit-space-for-delimiter-predicate))))
 
 ;;;###autoload
 (progn

racket-repl.el

@@ -1511,9 +1511,8 @@ identifier bindings and modules from the REPL's namespace.
   (add-to-list 'semantic-symref-filepattern-alist
                '(racket-repl-mode "*.rkt" "*.rktd" "*.rktl"))
   (when (boundp 'paredit-space-for-delimiter-predicates)
-    (add-hook 'paredit-space-for-delimiter-predicates
-              #'racket--paredit-space-for-delimiter-predicate
-              nil t)))
+    (setq-local paredit-space-for-delimiter-predicates
+                (list #'racket--paredit-space-for-delimiter-predicate))))
 
 (defun racket-repl-write-all-histories ()
   "Call `racket-repl-write-history' for all `racket-repl-mode' buffers.