Merge "Enable users to watch category membership changes #2"

diff --cc includes/DefaultSettings.php
Simple merge

diff --cc includes/api/i18n/en.json
Simple merge

diff --cc includes/api/i18n/qqq.json
Simple merge

diff --cc includes/changes/ChangesList.php
Simple merge

diff --cc includes/changes/EnhancedChangesList.php
Simple merge

diff --cc includes/changes/RecentChange.php
Simple merge

diff --cc includes/page/WikiPage.php
Simple merge

diff --cc includes/specialpage/ChangesListSpecialPage.php
Simple merge

diff --cc languages/i18n/en.json
Simple merge

diff --cc languages/i18n/qqq.json
Simple merge