Renamed two layouttools functions.

OLD:

    * layouttools.set_line_breaks_cyclically_by_line_duration_ge()
    * layouttools.set_line_breaks_cyclically_by_line_duration_in_seconds_ge()

NEW:

    * layouttools.set_line_breaks_by_line_duration_ge()
    * layouttools.set_line_breaks_by_line_duration_in_seconds_ge()

Doesn't need to appear in change log.