Move files in Phabricator one level up

Summary:
- `kill_init.php` said "Moving 1000 files" - I hope that this is not some limit in `FileFinder`.
- [src/infrastructure/celerity] `git mv utils.php map.php; git mv api/utils.php api.php`
- Comment `phutil_libraries` in `.arcconfig` and run `arc liberate`.

NOTE: `arc diff` timed out so I'm pushing it without review.

Test Plan:
/D1234
Browsed around, especially in `applications/repository/worker/commitchangeparser` and `applications/` in general.

Auditors: epriestley

Maniphest Tasks: T1103

src/applications/diffusion/controller/DiffusionPathCompleteController.php

@@ -0,0 +1,67 @@
+<?php
+
+/*
+ * Copyright 2012 Facebook, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+final class DiffusionPathCompleteController extends DiffusionController {
+
+  public function willProcessRequest(array $data) {
+    // Don't build a DiffusionRequest.
+  }
+
+  public function processRequest() {
+    $request = $this->getRequest();
+
+    $repository_phid = $request->getStr('repositoryPHID');
+    $repository = id(new PhabricatorRepository())->loadOneWhere(
+      'phid = %s',
+      $repository_phid);
+    if (!$repository) {
+      return new Aphront400Response();
+    }
+
+    $query_path = $request->getStr('q');
+    $query_path = ltrim($query_path, '/');
+    if (preg_match('@/$@', $query_path)) {
+      $query_dir = $query_path;
+    } else {
+      $query_dir = dirname($query_path);
+      if ($query_dir == '.') {
+        $query_dir = '';
+      }
+    }
+
+    $drequest = DiffusionRequest::newFromDictionary(
+      array(
+        'repository'  => $repository,
+        'path'        => $query_dir,
+      ));
+
+    $browse_query = DiffusionBrowseQuery::newFromDiffusionRequest($drequest);
+    $paths = $browse_query->loadPaths();
+
+    $output = array();
+    foreach ($paths as $path) {
+      $full_path = $query_dir.$path->getPath();
+      if ($path->getFileType() == DifferentialChangeType::FILE_DIRECTORY) {
+        $full_path .= '/';
+      }
+      $output[] = array('/'.$full_path, null, substr(md5($full_path), 0, 7));
+    }
+
+    return id(new AphrontAjaxResponse())->setContent($output);
+  }
+}