Changing cond to be more common lisp / emacs lisp like

Instead of:
  (cond (condition-1) (body-1)
        (condition-2) (body-2))

We now work like:

  (cond ((condition-1) (body-1)
         (condition-2) (body-2)))

hy/core/bootstrap.py

@@ -36,12 +36,11 @@ def defn_macro(tree):
 def cond_macro(tree):
     tree.pop(0)  # cond flag
     it = iter(tree)
-    conds = iter(zip(it, it))
-    test, branch = next(conds)
+    test, branch = next(it)
 
     root = HyExpression([HySymbol("if"), test, branch])
     ret = root
-    for (test, branch) in conds:
+    for (test, branch) in it:
         n = HyExpression([HySymbol("if"), test, branch])
         ret.append(n)
         ret = n

tests/native_tests/language.hy

@@ -78,8 +78,8 @@
 (defn test-cond []
   "NATIVE: test if cond sorta works."
   (cond
-    (= 1 2) (assert (= true false))
-    (is null null) (assert (= true true))))
+    ((= 1 2) (assert (= true false)))
+    ((is null null) (assert (= true true)))))
 
 
 (defn test-index []