[pylint] more work on the pylint support * uniformize usage of ClassDef and simplify related import * don't insert in the ast a python function but an astroid representation of that function * ignore __pkginfo__ file * drop attr-rgx, variable-rgx and argument-rgx, put the name in good-names instead * drop additional-builtins * add cell_call to the list of methods for which we don't want 'abstract-method'

missing-dep-for-interpreter make => make | build-essential | dpkg-dev (usr/*/cubicweb/skeleton/debian/rules.tmpl)