[repo] Drop _get_session method
it's not actually necessary but holds underlying _sessions dict handling.
Drop backward compat relying on it (which IMO should not be a problem).
Drop import of unused QueryError along the way.
[MASTER]
load-plugins=cubicweb.pylintext
ignore=__pkginfo__
[MESSAGES CONTROL]
disable = too-many-ancestors,too-many-instance-attributes,too-many-public-methods,
too-few-public-methods,too-many-arguments,import-error
[BASIC]
function-rgx = [a-z_][a-z0-9_]{2,35}$
good-names=w,_
[TYPECHECK]
generated-members=debug,info,notice,warning,error,critical,exception
[CLASSES]
exclude-protected=_cw,_cnx,
# namedtuple public API.
_asdict,_fields,_replace,_source,_make
[FORMAT]
max-line-length=100
max-module-lines=2000