Before this copyto would parse windows paths incorrectly.
This change moves the parsing code into fspath and makes sure
fspath.Split calls fspath.Parse which does the parsing correctly for
This also renames fspath.RemoteParse to fspath.Parse for consistency
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.