Convert raw strings to new syntax

tests/language/string_interpolate_test.dart

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 // Dart test program testing string interpolation.
 
 
 class WhatchamaCallIt {
   WhatchamaCallIt() { }
 
   String foo() {
@@ skipping 16 matching lines @@
   static String Printers;
   static String AAR_Printers;
 
   static testMain() {
     Printers = "Printers: $A and $B";
     AAR_Printers  = "AAR has $N $Printers.";
 
     var x = 1;
     var s = "eins und \$x macht zwei.";
     print(s);
-    Expect.equals(@"eins und $x macht zwei.", s);
+    Expect.equals(r"eins und $x macht zwei.", s);
 
     s = "eins und $x macht zwei.";
     print(s);
-    Expect.equals(@"eins und 1 macht zwei.", s);
+    Expect.equals(r"eins und 1 macht zwei.", s);
 
     print(AAR_Printers);
-    Expect.equals(@"AAR has 2 Printers: svin and hest.", AAR_Printers);
+    Expect.equals(r"AAR has 2 Printers: svin and hest.", AAR_Printers);
 
     var s$eins = "eins";
     var $1 = 1;
     var zw = "zw";
     var ei = "ei";
     var zw$ei = "\"Martini, dry? Nai zwai.\"";
     s = "${s$eins} und ${$1} macht $zw$ei.";
     print(s);
-    Expect.equals(@"eins und 1 macht zwei.", s);
+    Expect.equals(r"eins und 1 macht zwei.", s);
 
     var t = new ThingamaBob("Gretel");
     print(t.foo());
     Expect.equals(t.foo(), "Hansel and Gretel");
   }
 }
 
 main() {
   StringInterpolateTest.testMain();
 }