Merge "Allow callbacks to be passed to $wgContentHandlers"

diff --combined includes/DefaultSettings.php
index 6a41152,3ac3c8f..b9e5d2f
--- 1/includes/DefaultSettings.php
--- 2/includes/DefaultSettings.php
+++ b/includes/DefaultSettings.php
@@@ -75,7 -75,7 +75,7 @@@ $wgConfigRegistry = array
   * MediaWiki version number
   * @since 1.2
   */
 -$wgVersion = '1.27alpha';
 +$wgVersion = '1.27.0-alpha';
  
  /**
   * Name of the site. It must be changed in LocalSettings.php
@@@ -904,7 -904,8 +904,8 @@@ $wgMediaHandlers = array
  
  /**
   * Plugins for page content model handling.
-  * Each entry in the array maps a model id to a class name.
+  * Each entry in the array maps a model id to a class name or callback
+  * that creates an instance of the appropriate ContentHandler subclass.
   *
   * @since 1.21
   */