_s コミット[3f4effb] まで反映（翻訳含む）

  _s: Split navigation template tag in context-specific tags.
  _s: Update wpcom compat file to wrap contents in a hooked callback.
  _s: Use verbose syntax for conditionals in templates.
  Removed bullet that referenced keyboard-image-navigation.js, since that file was deleted.
  Fixed typo in inline comments.
  Add braces around single-line conditionals. See http://make.wordpress.org/core/2013/11/13/proposed-coding-standards-change-always-require-braces/.