Before this change the config file needed to be explicitly reloaded.
This coupled the config file implementation with the backends
needlessly.
This change stats the config file to see if it needs to be reloaded on
every config file operation.
This allows us to remove calls to
- config.SaveConfig
- config.GetFresh
Which now makes the the only needed interface to the config file be
that provided by configmap.Map when rclone is not being configured.
This also adds tests for configfile
If you are using rclone a library you can decide to use the rclone
config file system or not by calling
configfile.LoadConfig(ctx)
If you don't you will need to set `config.Data` to an implementation
of `config.Storage`.
Other changes
- change interface of config.FileGet to remove unused default
- remove MustValue from config.Storage interface
- change GetValue to return string or bool like elsewhere in rclone
- implement a default config file system which panics with helpful error
- implement getWithDefault to replace the removed MustValue
- don't embed goconfig.ConfigFile so we can change the methods
