Allow File type injection when used with @Binder for easy file upload handling

[tstirrat]

Allow the @Binder annotation to be used with a File object.

@ServiceMethod(name="TEST_SERVICE")
public void testService(@Binder(name="fileUpload") File fileUpload) {
  long modTime =  fileUpload.lastModified()
  if (fileUpload.exists()) {
    // do something
  }
}