ns: accept vector reference clauses; add Compiler/specials

Two general fixes shaken out by clojure/tools.macro.

- The ns macro now accepts a vector reference clause [:require …] / [:use …],
  not just the list form (:require …). Clojure dispatches on (first clause) and
  accepts both; jolt silently dropped vector clauses, so a ns written with them
  loaded with nothing required/used (tools.macro's test ns uses [:use …]).
- clojure.lang.Compiler/specials is now a static whose keys are the special-form
  symbols (matching Clojure 1.2/1.3). Macroexpansion tooling reads
  (keys Compiler/specials) to know which heads not to expand.

tools.macro itself isn't fully passing yet — its mexpand-all works, but the
macrolet/symbol-macrolet tests need letfn to macroexpand to letfn* (jolt models
letfn as a special form, not a macro over letfn*), so it stays off the list.

make test green (+1 corpus row, 0 new divergences), shakesmoke byte-identical.
One re-mint (the ns macro).

jolt-core/clojure/core/00-syntax.clj

@@ -117,7 +117,9 @@
   (let [nm (if (and (seq? nm) (= 'with-meta (first nm))) (second nm) nm)
         calls (reduce
                 (fn [acc clause]
-                  (if (seq? clause)
+                  ;; a reference clause may be a list (:require …) or a vector
+                  ;; [:require …]; Clojure accepts both, dispatching on (first clause).
+                  (if (or (seq? clause) (vector? clause))
                     (let [head (first clause) args (rest clause)]
                       (cond
                         (= head :require) (conj acc `(require ~@(map (fn [s] `(quote ~s)) args)))