The purpose of this is to make it easier to maintain and eventually to
allow the rclone backends to be re-used in other projects without
having to use the rclone configuration system.
The new code layout is documented in CONTRIBUTING.
This works by using a transform function to transform file names when
doing a compare when matching file names in a directory. rclone now
UTF-8 normalizes the file names and does a case insensitive compare if
the destination remote is case insensitive.
This deprecates the --local-no-unicode-normalization flag.
Fixes#1477
