Introduce an EnableSendfile directive (defaulted to ON) to allow users
  to disable sendfile mechanics for NFS volume mounts and other kernel
  objects that don't support sendfile.  And EnableSendfile off can be used
  to help narrow bugs down to the sendfile mechanics or eliminate the
  possiblity that sendfile is a factor on any given platform.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@97205 13f79535-47bb-0310-9956-ffa450edef68