Config System

[giulioungaretti]

Proposed config system, looks like what most python packages have:

• Configuration Object that is created at module import.
• Reads the main config that ships with the repo and sets it as default.
• If another config is found in the current HOME_DIR, then use that to update difference
• If another config is found in current directory then update with these values.
• Interface to create own customised configs and save them without the need to edit config files

I know @eendebakpt has a nice basic PR in #302, and the proposed solution looks a lot like that one.

[giulioungaretti]

This will solve most problems with the tight coupling of qcodes and jupyter.

[giulioungaretti]

f.ex #316, #278, #155, #290

[giulioungaretti]

@MerlinSmiles @eendebakpt do you two, biggest advocates of config, have preferences?
I am leaning toward a json based config file, which can be validated, and also created tweaked from a GUI, or yeah from an editor.

Others, please also say if you have preferences. I would not use a python file as it violates the principle of separating configuration data from code, which in the long run proves to be an effective way to avoid problems.

[peendebak]

No strong preferences. Either text (.ini) based or json is fine. No binary and no executable statements.

[MerlinSmiles]

I vote for json :) so much easier to work with than ini, the only downside is that it wont support comments...