Show coverage percentages in table of contents

Summary:
Rough cut -- this needs style / color / tooltips, etc. Show raw coverage and "modified coverage" (coverage on lines you touched) in the table of contents.

https://secure.phabricator.com/file/data/id3apce5p5gevkee6tg2/PHID-FILE-kxcxlbsej454t4xiht2o/Screen_Shot_2012-03-12_at_3.30.30_PM.png

Test Plan: See screenshot above.

Reviewers: tuomaspelkonen, btrahan, zeeg

Reviewed By: tuomaspelkonen

CC: aran, epriestley

Maniphest Tasks: T965

Differential Revision: https://secure.phabricator.com/D1864

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

@@ -208,9 +208,17 @@ final class DifferentialChangesetViewController extends DifferentialController {
 
     $output = $parser->render($range_s, $range_e, $mask);
 
+    $mcov = $parser->renderModifiedCoverage();
+
     if ($request->isAjax()) {
+      $content = array(
+        'coverage'  => array(
+          'differential-mcoverage-'.md5($changeset->getFilename()) => $mcov,
+        ),
+        'changeset' => $output,
+      );
       return id(new AphrontAjaxResponse())
-        ->setContent($output);
+        ->setContent($content);
     }
 
     Javelin::initBehavior('differential-show-more', array(