bisect: move 'printresult' in the 'hbisect' module
The logic is already extracted into a closure. We move it into the module
dedicated to bisect.
A minor change is applied: the creation of the 'displayer' is kept in the main
command function, it remove the needs to import 'cmdutil' in 'hbisect'. This
would create an import circle otherwise.
#require docutils gettext
$ $TESTDIR/check-gendoc fr
checking for parse errors