Rework retry logic when copying objects
Rework retry logic when copying objects

  * Fix off by one retry logic - fixes #406
  * Retry any retriable errors
  * Restructure code

olihey/rclone,yonjah/rclone,yonjah/rclone,arcimboldo/rclone,B4dM4n/rclone,arcimboldo/rclone,jackschmidt/rclone,B4dM4n/rclone,kynikos/rclone,olihey/rclone,jackschmidt/rclone,ncw/rclone,jackschmidt/rclone,olihey/rclone,seuffert/rclone,olihey/rclone,ncw/rclone,ncw/rclone,arcimboldo/rclone,arcimboldo/rclone,seuffert/rclone,seuffert/rclone,kynikos/rclone,kynikos/rclone,yonjah/rclone,B4dM4n/rclone,ncw/rclone,seuffert/rclone,B4dM4n/rclone,yonjah/rclone,kynikos/rclone,jackschmidt/rclone