fixes #43, remove => workaround

lib/src/js/printer.dart

Index: lib/src/js/printer.dart
diff --git a/lib/src/js/printer.dart b/lib/src/js/printer.dart
index 30288a7f211bcc3c322c22b4c46ca6cd9c5d429d..c8becbb40066bfc46ddaefbe3f4e1de3ee224312 100644
--- a/lib/src/js/printer.dart
+++ b/lib/src/js/printer.dart
@@ -844,9 +844,6 @@ class Printer implements NodeVisitor {
   }
 
   visitArrowFun(ArrowFun fun) {
-    if (fun.bindThisWorkaround) {
-      out("(");
-    }
     localNamer.enterScope(fun);
     if (fun.params.length == 1) {
       visitNestedExpression(fun.params.single, PRIMARY,
@@ -873,9 +870,6 @@ class Printer implements NodeVisitor {
       blockBody(fun.body, needsSeparation: false, needsNewline: false);
     }
     localNamer.leaveScope();
-    if (fun.bindThisWorkaround) {
-      out(").bind(this)");
-    }
   }
 
   visitLiteralBool(LiteralBool node) {