--files-from parses input files by ignoring comments starting with # and ;
and stripping whitespace from start and end of strings.
The --files-from-raw flag was added that reads every line from the file ignoring
comment characters and not stripping whitespace while maintaining
backwards compatibility.
Fixes#3762
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.
