Log Message:
Update shells/fish to 2.6.0.

Notable fixes and improvements:

- Jobs running in the background can now be removed from the list
  of jobs with the new disown builtin, which behaves like the same
  command in other shells.
- Command substitutions now have access to the terminal, like in
  other shells. This allows tools like fzf to work properly.
- In cases where the operating system does not report the size of
  the terminal, the COLUMNS and LINES environment variables are
  used; if they are unset, a default of 80x24 is assumed.
- New French and improved German translations.
- fish no longer depends on the which external command.

For full release notes see:

  http://www.fishshell.com/release_notes.html