Merge branch 'ja/i18n-similar-messages'

Merge branch 'ja/i18n-similar-messages'

Similar message templates have been consolidated so that
translators need to work on fewer number of messages.

* ja/i18n-similar-messages:
  i18n: turn even more messages into "cannot be used together" ones
  i18n: ref-filter: factorize "%(foo) atom used without %(bar) atom"
  i18n: factorize "--foo outside a repository"
  i18n: refactor "unrecognized %(foo) argument" strings
  i18n: factorize "no directory given for --foo"
  i18n: factorize "--foo requires --bar" and the like
  i18n: tag.c factorize i18n strings
  i18n: standardize "cannot open" and "cannot read"
  i18n: turn "options are incompatible" into "cannot be used together"
  i18n: refactor "%s, %s and %s are mutually exclusive"
  i18n: refactor "foo and bar are mutually exclusive"