Have manual ngx_pagespeed runs return exit code 0.
Have manual ngx_pagespeed runs return exit code 0.

wanrui/ngx_pagespeed,0x0mar/ngx_pagespeed,pagespeed/ngx_pagespeed,wanrui/ngx_pagespeed,digideskio/ngx_pagespeed,0x0mar/ngx_pagespeed,pagespeed/ngx_pagespeed,digideskio/ngx_pagespeed