Plottr original

Original plottr package, the final version of it.

It is distinct from new(er) plottr because it had two independent apps, plottr and inspectr, the former would just do live plotting by subscribing to qcodes dataset and establishing a socket connection, the latter just lists the runs in the dataset and opens the plottr window on double click of the run. At least the plottr that comes after this one, has these apps combined, is way more robust, defines a node framework for creating arbitrary analysis trees.