creation of passwordless "system" users for logged actions.
* $wgMaxSquidPurgeTitles was removed.
* $wgAjaxWatch was removed. This is now enabled by default.
+* (T27397) WebP is enabled by default as an uploadable filetype
=== New features in 1.27 ===
* $wgDataCenterId and $wgDataCenterRoles where added, which will serve as
setting in the relevant section of $wgLBFactoryConf.
* User::newSystemUser() may be used to simplify the creation of passwordless
"system" users for logged actions from scripts and extensions.
+* Extensions can now return detailed error information via the API when
+ preventing user actions using 'getUserPermissionsErrors' and similar hooks
+ by using ApiMessage instances instead of strings for the $result value.
==== External libraries ====
* WikiPage::doDeleteArticleReal() and WikiPage::doDeleteArticle() now
ignore the 2nd and 3rd arguments (formerly $id and $commit).
* Removed "loaderScripts" option from ResourceLoaderFileModule class.
+* Removed ORM-like wrapper added in 1.20.
== Compatibility ==