Swift: Use dump instead of println

With Swift 2.0 in Xcode7 the println function was renamed into
print. Use dump function instead which adds newlines like println.

Tests/SwiftMix/SwiftMain.swift

 @objc class SwiftMainClass {
   class func SwiftMain(argc:Int, argv:UnsafePointer<UnsafePointer<CChar>>) -> Int32 {
-    println("argc: \(argc)")
+    dump("argc: \(argc)")
     for (var i = 0; i < argc; ++i) {
       var argi = String.fromCString(argv[i])
-      println("arg[\(i)]: \(argi)");
+      dump("arg[\(i)]: \(argi)");
     }
     return 0;
   }

Tests/SwiftOnly/main.swift

-println("SwiftOnly")
+dump("SwiftOnly")