Add events framework to Arcanist

Test Plan:
Added a test event listener, added an event dispatch in diff workflow, run the
workflow, the listener was called.

Reviewers: epriestley

Reviewed By: epriestley

CC: aran, jungejason, epriestley

Differential Revision: 1102

scripts/arcanist.php

@@ -252,6 +252,13 @@ try {
     $workflow->setRepositoryAPI($repository_api);
   }
 
+  $listeners = $working_copy->getConfig('events.listeners');
+  if ($listeners) {
+    foreach ($listeners as $listener) {
+      id(new $listener())->register();
+    }
+  }
+
   $config->willRunWorkflow($command, $workflow);
   $workflow->willRunWorkflow();
   $err = $workflow->run();

src/__phutil_library_map__.php

@@ -35,6 +35,7 @@ phutil_register_library_map(array(
     'ArcanistDifferentialCommitMessageParserException' => 'differential/commitmessage',
     'ArcanistDifferentialRevisionRef' => 'differential/revision',
     'ArcanistDownloadWorkflow' => 'workflow/download',
+    'ArcanistEventType' => 'events/constant/type',
     'ArcanistExportWorkflow' => 'workflow/export',
     'ArcanistFilenameLinter' => 'lint/linter/filename',
     'ArcanistGeneratedLinter' => 'lint/linter/generated',
@@ -114,6 +115,7 @@ phutil_register_library_map(array(
     'ArcanistDiffUtilsTestCase' => 'ArcanistPhutilTestCase',
     'ArcanistDiffWorkflow' => 'ArcanistBaseWorkflow',
     'ArcanistDownloadWorkflow' => 'ArcanistBaseWorkflow',
+    'ArcanistEventType' => 'PhutilEventType',
     'ArcanistExportWorkflow' => 'ArcanistBaseWorkflow',
     'ArcanistFilenameLinter' => 'ArcanistLinter',
     'ArcanistGeneratedLinter' => 'ArcanistLinter',

src/events/constant/type/ArcanistEventType.php

@@ -0,0 +1,20 @@
+<?php
+
+/*
+ * Copyright 2011 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 ArcanistEventType extends PhutilEventType {
+}

src/events/constant/type/__init__.php

@@ -0,0 +1,12 @@
+<?php
+/**
+ * This file is automatically generated. Lint this module to rebuild it.
+ * @generated
+ */
+
+
+
+phutil_require_module('phutil', 'events/constant/type');
+
+
+phutil_require_source('ArcanistEventType.php');