Stability update
Stability update

 - Overall codebase stability enhancements
 - Check if headers is sent before write to head
 - Check if connection still open before write body, and closing it
 - Check stream for errors when piping data (including 3rd party
storage)
 - Handle abort (e.g. browser close/refresh) (including 3rd party
storage)
 - Update `Content-Disposition` header to meet RFC 5987
 - Attempt to fix #417 , thanks to @Twisterking

VeliovGroup/Meteor-Files