[FIX] win32: use 'net' command for service start/stop operation

[FIX] win32: use 'net' command for service start/stop operation

  * We have to wait for complete service stop before trying to re-start
    OpenERP service, otherwise service manager will complain that the
    service is already running - and thus preventing to it start.
      'sc' command only send a query to service manager without waiting
    for completion - instead we use 'net' command which wait for complete
    start/stop operation.

bzr revid: xal@openerp.com-20130107162302-xtf44nm10859203w