[Enhancement] Separate config from metadata

[YarnSphere]

The metadata being in the same file as the rest of the configuration makes it awkward to manage the config: as I'm sure many do, I manage the configuration for programs/tools I use by tracking it within a Git repo. Having the file change whenever there is a new connection is a bit annoying.

Except for maybe being a bit more annoying to handle in code, I don't think there would be any downsides to simply separating the file in two: pvpn-cli.cfg and pvpn-cli-meta.cfg or something along those lines.

Thoughts?

[Rafficer]

Not a bad idea. This could go hand in hand with the changes proposed in #96. Would also make it possible to switch the metadata file to json, which would preserve value types.