Move to logging for CTESLO

As now the error messages are crude sys.stderr.write calls. The logging package is higher-level, cleaner and support code split into several modules (so libcteslo…) and thus would be better suited for this purpose

subprocess shouldn't be used, except inside plugins for CTESLO

From the very beginning cteslo has been using subprocess.Popen and his siblings (call…) for plugin use. This is messy at best and makes several features like logging, graceful error management impossible. Thus the need to move all this to a cleaner flow: plugins will now need a script in python3 (as is already the c...

Integrate the Unitex ressources as in Matthieu Constant's lgtools for CTESLO

Using extract-text-property

Make a command that prints available formats and tools for CTESLO

The title said it all.

Add support for outputting tagged trs for CTESLO

Since trs is ubiquitously used for ESLO and is available as input it would be nice if there were an option for outputting trs files natively in CTESLO. Of course it would need an extension of the trs format, since it doesn't includes lexeme segmentation and tags yet.