Muck around with Diviner method documentation display

Summary:
Ref T988. Not sure about this, feel free to push back or tweak it or whatever, but I want to reduce the amount of meta-text in the method documentation. Primarily this:

  - Shortens "From parent implementation in ClassName:" to "ClassName".
  - Tries to tweak the styles a bit so that it's relatively obvious what that means (hopefully?).
  - Fixes an issue with tasks where some methods could be ignored.

Test Plan: {F57565}

Reviewers: chad

Reviewed By: chad

CC: aran

Maniphest Tasks: T988

Differential Revision: https://secure.phabricator.com/D6911

src/applications/files/engine/PhabricatorFileStorageEngine.php

@@ -9,12 +9,18 @@
  *
  * For more information, see @{article:File Storage Technical Documentation}.
  *
+ * @task construct Constructing an Engine
  * @task meta Engine Metadata
  * @task file Managing File Data
  * @group filestorage
  */
 abstract class PhabricatorFileStorageEngine {
 
+  /**
+   * Construct a new storage engine.
+   *
+   * @task construct
+   */
   final public function __construct() {
     // <empty>
   }

src/applications/files/engine/PhabricatorS3FileStorageEngine.php

@@ -4,20 +4,17 @@
  * Amazon S3 file storage engine. This engine scales well but is relatively
  * high-latency since data has to be pulled off S3.
  *
- * @task impl       Implementation
- * @task internal   Internals
- * @group filestorage
+ * @task internal Internals
  */
 final class PhabricatorS3FileStorageEngine
   extends PhabricatorFileStorageEngine {
 
+
 /* -(  Implementation  )----------------------------------------------------- */
 
 
   /**
-   * This engine identifies as "amazon-s3".
-   *
-   * @task impl
+   * This engine identifies as `amazon-s3`.
    */
   public function getEngineIdentifier() {
     return 'amazon-s3';
@@ -25,8 +22,7 @@ final class PhabricatorS3FileStorageEngine
 
 
   /**
-   * Write file data into S3.
-   * @task impl
+   * Writes file data into Amazon S3.
    */
   public function writeFile($data, array $params) {
     $s3 = $this->newS3API();
@@ -55,8 +51,7 @@ final class PhabricatorS3FileStorageEngine
 
 
   /**
-   * Load a stored blob from S3.
-   * @task impl
+   * Load a stored blob from Amazon S3.
    */
   public function readFile($handle) {
     $result = $this->newS3API()->getObject(
@@ -74,8 +69,7 @@ final class PhabricatorS3FileStorageEngine
 
 
   /**
-   * Delete a blob from S3.
-   * @task impl
+   * Delete a blob from Amazon S3.
    */
   public function deleteFile($handle) {
     AphrontWriteGuard::willWrite();