Fix help command execute on custom.

See merge request !1989

Fix Qtech.QSW2800.get_inventory datetime import.

See merge request !1987

LineTokenizer: Fix string_quote processing

See merge request !1986

ipam: Policy defaults in "New Prefix" form

See merge request !1978

2to3 metaclass

See merge request !1985

Port legacy tests

See merge request !1984

2to3 set literal

See merge request !1983

2to3 basestring

See merge request !1982

Move MongoCache index creation into ensure-indexes

See merge request !1959

del_with_statement

See merge request noc/noc!1981

2to3 idioms

See merge request noc/noc!1980

Bye-bye HG

See merge request noc/noc!1872

test: Report empty module's docstrings

See merge request noc/noc!1910

lib.app cleanup

See merge request noc/noc!1976

flake8_f401_webapp_crm

See merge request noc/noc!1969

flake8_f401_webapp_dns

See merge request noc/noc!1970

flake8_f401_webapp_fm

See merge request noc/noc!1971

flake8_f401_webapp_gis

See merge request noc/noc!1972

flake8_f401_webapp_inv

See merge request noc/noc!1973

flake8_f401_webapp_main

See merge request noc/noc!1974

flake8_f401_webapp_maintenance

See merge request noc/noc!1975

flake8_f401_webapp_cm

See merge request noc/noc!1968