config.ini is now overloaded, hacky

[hackalog]

We've now overloaded the config.ini to include both paths[] info, and local dataset configuration. This is fragile in two ways:

1. references to local_config (paths._config) rely on the implementation of paths - not ideal
2. if you have a dataset named "Paths", you're in trouble.

To solve #2, we should reallty build a KVSingleton that is a 2-level dictionary config[section][key] mapping to an ini

Otherwise, behavior should be the same (should still be a singleton, e.g.)

to solve #1, just implement the config 2-level singleton and leave paths alone, or have paths[] inherenely reference as section called "_paths"

[hackalog]

Could fix #2 more simply by namespacing the sections:

[Dataset:whatever]
[Paths]