else and else-if support.

examples/if_else_test.fun

@@ -0,0 +1,24 @@
+#!/usr/bin/env fun
+
+// Test else / else if chains and nested if-blocks (two-space indentation)
+
+print("=== if/else-if/else test ===")
+
+number n = 42
+
+if (n < 0)
+  print("neg")
+else if (n == 0)
+  print("zero")
+else if (n < 10)
+  print("small")
+else
+  print("big")        // expect: big
+
+// Nested if inside a true branch
+if (n >= 10)
+  print(n)            // expect: 42
+  if (n == 42)
+    print("answer")   // expect: answer
+
+print("=== if/else-if/else done ===")