Make inline comment preview work in Diffusion

Summary: created a PhabricatorInlineCommentPreviewController so controllers in Diffusion and Differential respectively just have to handle the URI mapping and data loading like good little controllers.

Test Plan:
left inline comments on commits, deleted inline commits, submitted inline comments -- all worked well
did the same on some diffs

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, Korvin

Maniphest Tasks: T1176

Differential Revision: https://secure.phabricator.com/D3034

src/applications/diffusion/controller/DiffusionCommitController.php

@@ -264,7 +264,7 @@ final class DiffusionCommitController extends DiffusionController {
         '/diffusion/'.$callsign.'/diff/?view=r');
 
       $change_list->setInlineCommentControllerURI(
-        '/diffusion/inline/'.phutil_escape_uri($commit->getPHID()).'/');
+        '/diffusion/inline/edit/'.phutil_escape_uri($commit->getPHID()).'/');
 
       // TODO: This is pretty awkward, unify the CSS between Diffusion and
       // Differential better.
@@ -580,6 +580,8 @@ final class DiffusionCommitController extends DiffusionController {
         'auditors' => 'add-auditors-tokenizer',
         'ccs'      => 'add-ccs-tokenizer',
       ),
+      'inline'     => 'inline-comment-preview',
+      'inlineuri'  => '/diffusion/inline/preview/'.$commit->getPHID().'/',
     ));
 
     $preview_panel =
@@ -589,6 +591,8 @@ final class DiffusionCommitController extends DiffusionController {
             Loading preview...
           </div>
         </div>
+        <div id="inline-comment-preview">
+        </div>
       </div>';
 
     return