serializable and hashable BitArray. Comparable BitList. Small improvements

docs/samples/happy_numbers.lyng.bad

@@ -21,10 +21,10 @@ import lyng.time
 //
 // After all optimizations it takes ~120ms.
 //
-//for( r in 1..100 ) {
-//    val start = Instant.now()
+for( r in 1..100 ) {
+    val start = Instant.now()
     val found = naiveCountHappyNumbers()
-//    println("Found happy numbers: %d time %s"(found, Instant.now() - start))
+    println("Found happy numbers: %d time %s"(found, Instant.now() - start))
     assert( found == 55252 )
-//    delay(0.01)
-//}
+    delay(0.1)
+}