Update to 1.845
    
    - New upstream release 1.845
      - Croak if is_joinable, is_running, or join is called by a non-managed
        process in MCE::Child; added LIMITATION section to the documentation
      - Improved is_joinable, is_running, list_joinable, and list_running in
        MCE::Child
      - Added example (consumer requests item) to MCE::Channel documentation
      - Support the task_end option regardless of whether user_tasks is specified
      - Support IO::All::{ File, Pipe, STDIO } for input data including output
        via MCE->print($io, ...), printf, and say
      - Support gather ⇒ MCE::Candy::out_iter_fh($io) using MCE::Candy