Ticket #2966: fix view of broken manpages.

Initial commit: create MC pipe class to capture stdout and stderr of
spawn processes.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
mcviewer: use mc_pipe_t to show command output.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
Update po/*.po files.

Signed-off-by: Andrew Borodin <aborodin@vmail.ru>
Merge branch '2966_view_broken_manpage'

* 2966_view_broken_manpage:
  Update po/*.po files.
  mcviewer: use mc_pipe_t to show command output.
  Ticket #2966: fix view of broken manpages.