Extensions control

[susuhahnml]

Allow new extensions to access important pots of the process.

I am thinking of something similar to what is done with the Application class of clingo but which would be called in the incremental process within telingo. My motivation here would be to allow access to the stable models found in this process and give easy access to the timepoints in which predicate hold, so that any extension can manage them before they are added as the last argument. Maybe this gives the potential to other internal configurations for these extensions but I am not sure about this part yet. Perhaps it could even make easier adding new translation rules for a theory as part of the extension class instead of doing so within the code (Like the extension done for 'del' or even 'tel').

[rkaminsk]

This might be interesting: https://github.com/potassco/tefoli. It was made for using theories written in C with Python. telingo could implement a similar interface. The interface would have to be extended to account for incremental solving though.