Review the `lodkit` importer

[lu-pl]

Generally review the lodkit importer.

Should the importer be available at import lodkit?
Does the importer conflict with any import mechanics?
...

[lu-pl]

The lodkit graph importer probably should not get registered on any import and modify the global interpreter state implicitly.

An interesting design would be to allow explicit global scoping, context scoping and callable scoping for the importer functionality:

# global 
enable_graph_import() 
disable_graph_import() 

# context scoped 
with enable_graph_import():
    ... 

# function scoped 
@enable_graph_import()
def f(): ...

[lu-pl]

The above proposal will not be implemented, I consider it a bad code smell to make an importer available for lexical contexts only; this implies use of the import statement in such contexts, which is not PEP8-compliant at all.

Instead, the importer could be registered by calling from lodkit import enable_graph_import or the like. This would outsource the activation logic to a module-level hook, maybe that's cool.

First of all, the importer needs urgent fixing though. The current implementation is wonky on several accounts. PEP 302 must be consulted and studied carefully.