Sync with 'maint'

* maint: Correct common spelling mistakes in comments and tests kwset: fix spelling in comments precompose-utf8: fix spelling of "want" in error message compat/nedmalloc: fix spelling in comments compat/regex: fix spelling and grammar in comments obstack: fix spelling of similar contrib/subtree: fix spelling of accidentally git-remote-mediawiki: spelling fixes doc: various spelling fixes fast-export: fix argument name in error messages Documentation: distinguish between ref and offset deltas in pack-format i18n: make the translation of -u advice in one go