Add Basic Auditing Functionalities

Summary:
add basic auditing functionalities. For the related commits for a
package, we detect the following conditions which might be suspicious to the
owners of the package:

* no revision specified
* revision not found
* author not match
* reviewedby not match
* owners not involved
* commit author not recognized

The owners of the package can change the status of the audit entries by
accepting it or specify concern.

The owner can turn on/off the auditing for a package.

Test Plan:
*  verified that non-owner cannot see the details of the audit and cannot modify
it
*  verified that all the audit reasons can be detected
*  tested dropdown filtering and package search
*  verified really normal change not detected
*  verified accept/concern a commit
*  tested enable/disable a package for auditing
*  verified one audit applies to all <commit, packages> to the packages the
auditor owns
*  verified that re-parsing a commit won't have effect if there exists a
 relationship for <commit, package> already

Reviewers: epriestley, nh

Reviewed By: epriestley

CC: aran, benmathews, btrahan, mpodobnik, prithvi, TomL, epriestley

Differential Revision: 1242

src/view/form/control/textarea/AphrontFormTextAreaControl.php

@@ -23,13 +23,24 @@ class AphrontFormTextAreaControl extends AphrontFormControl {
   const HEIGHT_VERY_TALL  = 'very-tall';
 
   private $height;
+  private $readOnly;
   private $enableDragAndDropFileUploads;
 
+
   public function setHeight($height) {
     $this->height = $height;
     return $this;
   }
 
+  public function setReadOnly($read_only) {
+    $this->readOnly = $read_only;
+    return $this;
+  }
+
+  protected function getReadOnly() {
+    return $this->readOnly;
+  }
+
   protected function getCustomControlClass() {
     return 'aphront-form-control-textarea';
   }
@@ -69,6 +80,7 @@ class AphrontFormTextAreaControl extends AphrontFormControl {
       array(
         'name'      => $this->getName(),
         'disabled'  => $this->getDisabled() ? 'disabled' : null,
+        'readonly'  => $this->getReadonly() ? 'readonly' : null,
         'class'     => $height_class,
         'style'     => $this->getControlStyle(),
         'id'        => $id,