Correct whitespace option is passed to 'Show All Lines' request.

Summary:
Expanding lines duplicated some lines occasionally, because whitespace
option was different for the original request and the following request.

Test Plan:
Tested that the broken changeset was correct now.

Reviewed By: epriestley
Reviewers: epriestley
CC: jungejason, aran, epriestley
Differential Revision: 263

src/applications/differential/controller/changesetview/DifferentialChangesetViewController.php

@@ -189,6 +189,7 @@ class DifferentialChangesetViewController extends DifferentialController {
 
     Javelin::initBehavior('differential-show-more', array(
       'uri' => '/differential/changeset/',
+      'whitespace' => $request->getStr('whitespace'),
     ));
 
     $detail = new DifferentialChangesetDetailView();

webroot/rsrc/js/application/differential/behavior-show-more.js

@@ -26,6 +26,7 @@ JX.behavior('differential-show-more', function(config) {
       JX.DOM.setContent(container, 'Loading...');
       JX.DOM.alterClass(context, 'differential-show-more-loading', true);
       var data = e.getNodeData('show-more');
+      data['whitespace'] = config.whitespace;
       new JX.Request(config.uri, JX.bind(null, onresponse, e))
         .setData(data)
         .send();