Merge "Create ChangeTagsUpdate hook"

diff --combined includes/changes/RecentChange.php
index 584c813,ec915f0..1262f2c
--- 1/includes/changes/RecentChange.php
--- 2/includes/changes/RecentChange.php
+++ b/includes/changes/RecentChange.php
@@@ -333,7 -333,7 +333,7 @@@ class RecentChange 
  
                if ( count( $this->tags ) ) {
                        ChangeTags::addTags( $this->tags, $this->mAttribs['rc_id'],
-                               $this->mAttribs['rc_this_oldid'], $this->mAttribs['rc_logid'], null );
+                               $this->mAttribs['rc_this_oldid'], $this->mAttribs['rc_logid'], null, $this );
                }
  
                # Notify external application via UDP
@@@ -1037,13 -1037,9 +1037,13 @@@
         *
         * @since 1.28
         *
 -       * @param array $tags
 +       * @param string|array $tags
         */
        public function addTags( $tags ) {
 -              $this->tags = array_merge( $tags, $this->tags );
 +              if ( is_string( $tags ) ) {
 +                      $this->tags[] = $tags;
 +              } else {
 +                      $this->tags = array_merge( $tags, $this->tags );
 +              }
        }
  }