Revert "removing unused extension extensions/Translate"

This reverts commit d50d824808a35b1ba5ad912f1a20fd78f677f08f.
Revert "removing unused extension Contest"

This reverts commit cd2de3004aa09b8dc62f47527affc804a1ad2c72.
Revert "removing unused extension extensions/CentralAuth"

This reverts commit 7c943c7009b47140fdb7ad15bf4de176926d6356.