Added fallback to fake worker if serialization of typed array fails.

This happens e.g. in Opera 11.60.

src/core.js

@@ -605,7 +605,13 @@ var PDFDoc = (function PDFDocClosure() {
       }.bind(this));
 
       var testObj = new Uint8Array(1);
+      // Some versions of Opera throw a DATA_CLONE_ERR on serializing the typed array.
+      // If such an error occurs, we fallback to a faked worker.
+      try {
         messageHandler.send('test', testObj);
+      } catch (e) {
+        this.setupFakeWorker();
+      }
     } else {
       this.setupFakeWorker();
     }