lfs: enable the extension locally after sharing a repo with 'lfs' requirement This is consistent with clone in the previous commit.

lfs: enable the extension locally after cloning a repo with 'lfs' requirement We do the same thing on clone for the largefiles extension, as a convenience. Similar to largefiles, it's probably safer to only enable this extension on a per repo basis because it is trivial to add an lfs file. And that gives the repository some centralized VCS characteristics.

log: translate column labels at once (issue5750) This makes sure that all columns are aligned. getlogcolumns() is hosted by templatekw so the namespaces module can see it. i18n/de.po is updated so test-log.t passes with no error. "obsolete:" and "instability:" are kept untranslated.