Ticket 48923 - serverCmd timeout not working as expected
    
    Bug Description:  When trying to start a server, and the startup fails,
                      the start-dirsrv command will actually hang for quite
                      a while, and the current timeout implementation does
                      not apply to this scenario.
    
    Fix Description:  Instead of calling "os.system()", use subprocess and
                      a timer that will kill the process if it timeouts.
    
    https://fedorahosted.org/389/ticket/48923
    
    Reviewed by: nhosoi(Thanks!)