handle mavlink packets

def mavlink_packet(self, m):
        '''handle mavlink packets'''
        # can't use status.msgs as we need this filtered to our target system
        if (self.settings.target_system != 0 and
            self.settings.target_system != m.get_srcSystem()):
            return
        if m.get_type() == 'GPS_RAW_INT':
            self.fix_type = m.fix_type
        if m.get_type() == 'SYSTEM_TIME':
            self.time_boot_ms = m.time_boot_ms