Use regular expression to match content type in BinaryResponseHandler

This allows the developer a bit more flexibility in picking which content types to allow. This is fully backwards compatible. 

For example, to all downloading of all file types:
```java
private static final String[] ALLOWED_CONTENT_TYPES = {".*"};

AsyncHttpResponseHandler responseHandler = new BinaryResponseHandler(ALLOWED_CONTENT_TYPES) {
   @Override
   public void onSuccess(int statusCode, byte[] data) {
      ...
   }
}
```