Google Code-in

Your task is to solve the following three small Phabricator tasks relating to the MediaWiki core software:

• Complete the checklist posted by Spage to fully deprecate the UnknownAction hook (https://phabricator.wikimedia.org/T54027)
• Provide a new $wg... setting which defines the timeout used when downloading XML data from another wiki as part of the import process (discussed in comments at https://phabricator.wikimedia.org/T17000)
• Analyse the issue described at https://phabricator.wikimedia.org/T13378, and if you can consistently cause the error to be displayed (you may need to enable debug logging), provide a patch that fixes the issue.

These unrelated issues should be dealt with in separate patches.