MAJOR clean up of graph_refs_meta.py.

Now makes use of several shortcut functions and dictionaries. 
Adding new keys, as they come online, will be a breeze.

To illustrate the power of the shortcuts:
`graph_refs_meta.py` is about 10K smaller while `graph_refs_meta.json` is about 30K bigger
than before.

Table of content at the top of `graph_refs_meta.py` and 
many `ctrl-f`-friendly comments.

Better descriptions, as they are now shown online. ;)
More work is needed though.

Polar chart objects are not filled in.