vars.Fetch should take only var key to resolve value

[Chaitanyabsprip]

No description provided.

[rwxrob]

I woke up with the idea of adding the vars.Driver to bonzai again and actually triggering persistence from Set and hinting at it with Var.Persist. Let me try that.

[rwxrob]

I am warming up to the idea of having both bonzai.Persistence and Cmd.WithPersistence() as well. I feel like if we do this right the only thing command developers would ever need would be Cmd.Vars and Cmd.Set/Get. All the other stuff is just external tools for dealing with specific bonzai.Persister implementations. In fact, I really want this because I can create a cloud-based persister for stuff I want to be able to use all over and leave the other stuff to localized things. Sounds like you like it as well. I'll go for it during my next mini-sprint (probably tonight).

[Chaitanyabsprip]

You're right, I like it as well, I just have a question about the scope of the Persister, see #275 (comment)