mediawiki: Update to 1.20.7

(cherry picked from commit 81a9f72d7c4e95d79a928e856cbd2179485a1502)
php: Update to 5.4.21

(cherry picked from commit 3d6728a1227f6a2c846b868ede8ebe542826f95d)
linux: Update to 3.4.69

(cherry picked from commit 45462d0bc479a970061eb763c57a704f48c24bf1)