Bundled Themes: Bump version numbers and update changelogs for 4.9 release

* Also, updates POT files for Twenty Ten and Twenty Eleven.

Props lemacarl, maedahbatool, mrahmadawais, davidakennedy.

Fixes #42090.

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git-svn-id: https://core.svn.wordpress.org/trunk@41934 1a063a9b-81f0-0310-95a4-ce76da25c4cd