Add tasks for all the new languages

Task/Polymorphism/Swift/polymorphism.swift

@@ -0,0 +1,46 @@
+class RCPoint : Printable {
+  var x: Int
+  var y: Int
+  init(x: Int = 0, y: Int = 0) {
+    self.x = x
+    self.y = y
+  }
+  convenience init(p: RCPoint) {
+    self.init(x:p.x, y:p.y)
+  }
+  var description: String {
+  return "<RCPoint x: \(self.x) y: \(self.y)>"
+  }
+}
+
+class RCCircle : RCPoint {
+  var r: Int
+  init(p: RCPoint, r: Int = 0) {
+    self.r = r
+    super.init(x:p.x, y:p.y)
+  }
+  init(x: Int = 0, y: Int = 0, r: Int = 0) {
+    self.r = r
+    super.init(x:x, y:y)
+  }
+  convenience init(c: RCCircle) {
+    self.init(x:c.x, y:c.y, r:c.r)
+  }
+  override var description: String {
+    return "<RCCircle x: \(x) y: \(y) r: \(r)>"
+  }
+}
+
+println(RCPoint())
+println(RCPoint(x:3))
+println(RCPoint(x:3, y:4))
+println(RCCircle())
+println(RCCircle(x:3))
+println(RCCircle(x:3, y:4))
+println(RCCircle(x:3, y:4, r:7))
+let p = RCPoint(x:1, y:2)
+println(RCCircle(p:p))
+println(RCCircle(p:p, r:7))
+println(p.x) // 1
+p.x = 8
+println(p.x) // 8