Fix: tools, libcrmcommon: Reopen the output dest on reset.
    
    This is needed when running crm_mon as a daemon.  When we do a reset,
    we need to clear out any existing output destination and start writing
    again from the beginning.  This really only matters when the destination
    is a file.
    
    The extra freopen at the end of crm_mon is to handle when crm_mon is
    killed.  We need to reset the output file to its beginning before
    calling finish.