added list_connectives script from PCC repo (incl. commit history)
added documentation to list_connectives.py
fixes #205: list_connectives.py now handles modified connectives
improved error message in list_connectives.py
get_connectives() now handles multiple connectives w/ the same ID
get_connective_string() now handles connectives w/ and w/out modifiers and strips surrounding space
outsourced function to get connective modifier (str)
list_connectives.py output now handles multiple connectives w/ the same ID
fixed get_connective_string(): it tried to strip element.text even if it was None
added ipynb that aims at fixing conano files
added get_ancestor_units() to conano script
conano: removed unused import
flake8: reformatting; refactoring output variants into functions
renamed list_connectives.py to conano.py