Add tasks for all the new languages

Task/Factorial/Wart/factorial-1.wart

@@ -0,0 +1,4 @@
+def (fact n)
+  if (n = 0)
+    1
+    (n * (fact n-1))

Task/Factorial/Wart/factorial-2.wart

@@ -0,0 +1,5 @@
+def (fact n)
+  (n * (fact n-1))
+
+def (fact 0)
+  1

Task/Factorial/Wart/factorial-3.wart

@@ -0,0 +1,4 @@
+def (fact n)
+  ret result 1
+    for i 1 (i <= n) ++i
+      result <- result*i

Task/Factorial/Wart/factorial-4.wart

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+# a useful helper to generate all the natural numbers until n
+def (nums n)
+  collect+for i 1 (i <= n) ++i
+    yield i
+
+def (fact n)
+  (reduce (*) nums.n 1)