Correct PHPDoc or add default return for numerous methods

Summary:
Correct PHPDoc when none of the method calls try to handle a return value.
Add missing fallback `return` statements (which may never be reached if previous condition checks were always true).

This reduces the amount of errors reported by static code analysis tools.

Test Plan: Carefully read the code and check all places in which a function gets called whether a return value is expected.

Reviewers: O1 Blessed Committers, valerio.bozzolan

Reviewed By: O1 Blessed Committers, valerio.bozzolan

Subscribers: tobiaswiese, valerio.bozzolan, Matthew, Cigaryno

Differential Revision: https://we.phorge.it/D25650

src/aphront/configuration/AphrontApplicationConfiguration.php

@@ -523,6 +523,7 @@ final class AphrontApplicationConfiguration
         return array($result->getController(), $result->getURIData());
       }
     }
+    return null;
   }
 
   private function buildSiteForRequest(AphrontRequest $request) {

src/applications/people/storage/PhabricatorUserEmail.php

@@ -231,7 +231,6 @@ final class PhabricatorUserEmail
    *
    * @param PhabricatorUser The user sending the notification.
    * @param PhabricatorUserEmail New primary email address.
-   * @return this
    * @task email
    */
   public function sendOldPrimaryEmail(

src/applications/phame/storage/PhamePost.php

@@ -268,6 +268,7 @@ final class PhamePost extends PhameDAO
       case self::MARKUP_FIELD_BODY:
         return $this->getBody();
     }
+    return null;
   }
 
   public function didMarkupText(

src/infrastructure/daemon/workers/PhabricatorWorker.php

@@ -262,7 +262,6 @@ abstract class PhabricatorWorker extends Phobject {
    * you are using queues to improve locking behavior).
    *
    * @param map<string, wild> Optional default options.
-   * @return this
    */
   final public function flushTaskQueue($defaults = array()) {
     foreach ($this->getQueuedTasks() as $task) {

src/infrastructure/edges/editor/PhabricatorEdgeEditor.php

@@ -90,7 +90,6 @@ final class PhabricatorEdgeEditor extends Phobject {
    * (e.g., adds followed by removals) if their outcomes are not dependent,
    * since transactions will not be held open as long.
    *
-   * @return this
    * @task edit
    */
   public function save() {

support/startup/PhabricatorStartup.php

@@ -317,7 +317,6 @@ final class PhabricatorStartup {
    * @param   Throwable The exception itself.
    * @param   bool      True if it's okay to show the exception's stack trace
    *                    to the user. The trace will always be logged.
-   * @return  exit      This method **does not return**.
    *
    * @task apocalypse
    */