Merge "startup: Drop JavaScript support for ES3-only browsers"

diff --combined RELEASE-NOTES-1.29
index 9e49e56,33d084c..6dbc749
--- 1/RELEASE-NOTES-1.29
--- 2/RELEASE-NOTES-1.29
+++ b/RELEASE-NOTES-1.29
@@@ -63,17 -63,15 +63,17 @@@ production
  === External library changes in 1.29 ===
  
  ==== Upgraded external libraries ====
 -* Added wikimedia/timestamp v1.0.0.
  * Updated QUnit from v1.22.0 to v1.23.1.
 -* Updated cssjanus from v1.1.2 to 1.1.3.
 +* Updated cssjanus from v1.1.2 to v1.2.0.
  * Updated psr/log from v1.0.0 to v1.0.2.
  * Update Moment.js from v2.8.4 to v2.15.0.
 -* Updated oyejorge/less.php from v1.7.0.10 to v1.7.0.13.
 -* Added wikimedia/remex-html v1.0.1.
 +* Updated oyejorge/less.php from v1.7.0.10 to v1.7.0.14.
 +* Updated monolog from v1.18.2 to 1.22.1.
 +* Updated wikimedia/composer-merge-plugin from v1.3.1 to v1.4.0.
  
  ==== New external libraries ====
 +* Added wikimedia/timestamp v1.0.0.
 +* Added wikimedia/remex-html v1.0.1.
  
  ==== Removed and replaced external libraries ====
  
@@@ -283,6 -281,8 +283,8 @@@ changes to languages because of Phabric
    rather than <strong> tags. The old class name, "selflink", was deprecated
    and will be removed in a future release. (T160480)
  * (T156184) $wgRawHtml will no longer apply to internationalization messages.
+ * Browser support for non-ES5 JavaScript browsers, including Android 2, Opera 12,
+   and Internet Explorer 9, was lowered from Grade A to Grade C.
  
  == Compatibility ==