Fix symbol URI generation to include default branch name for relevant repositories

Summary: We need to build a request in order to pick up an appropriate default branch name, instead of using the raw static generator.

Test Plan: Clicked a symbol link, got /master/path/blahblah

Reviewers: vrana, btrahan

Reviewed By: vrana

CC: aran, epriestley

Differential Revision: https://secure.phabricator.com/D1982

src/applications/diffusion/controller/symbol/DiffusionSymbolController.php

@@ -145,7 +145,6 @@ final class DiffusionSymbolController extends DiffusionController {
         '',
         '',
         '',
-        'n'
       ));
     $table->setNoDataString(
       "No matching symbol could be found in any indexed project.");

src/applications/repository/storage/symbol/PhabricatorRepositorySymbol.php

@@ -45,10 +45,13 @@ final class PhabricatorRepositorySymbol extends PhabricatorRepositoryDAO {
   }
 
   public function getURI() {
-    return DiffusionRequest::generateDiffusionURI(
+    $request = DiffusionRequest::newFromDictionary(
+      array(
+        'repository'  => $this->getRepository(),
+      ));
+    return $request->generateURI(
       array(
         'action'    => 'browse',
-        'callsign'  => $this->getRepository()->getCallsign(),
         'path'      => $this->getPath(),
         'line'      => $this->getLineNumber(),
       ));