Merge lp://staging/~barry/update-manager/janitor-refactor into lp://staging/~canonical-foundations/update-manager/py3

DistUpgrade/DistUpgradeQuirks.py (+1/-1)
DistUpgrade/build-exclude.txt (+3/-1)
DistUpgrade/build-tarball.sh (+1/-1)
debian/update-manager-core.dirs (+1/-1)
debian/update-manager-core.install (+1/-2)
janitor/__init__.py (+24/-0)
janitor/plugincore/NEWS.rst (+7/-0)
janitor/plugincore/__init__.py (+17/-0)
janitor/plugincore/core/file_cruft.py (+53/-0)
janitor/plugincore/core/missing_package_cruft.py (+52/-0)
janitor/plugincore/core/package_cruft.py (+61/-0)
janitor/plugincore/cruft.py (+159/-0)
janitor/plugincore/docs/README.rst (+201/-0)
janitor/plugincore/exceptions.py (+42/-0)
janitor/plugincore/i18n.py (+34/-0)
janitor/plugincore/manager.py (+185/-0)
janitor/plugincore/plugin.py (+81/-0)
janitor/plugincore/plugins/deb_plugin.py (+42/-0)
janitor/plugincore/plugins/dpkg_status_plugin.py (+80/-0)
janitor/plugincore/plugins/kdelibs4to5_plugin.py (+51/-0)
janitor/plugincore/plugins/langpack_manual_plugin.py (+76/-0)
janitor/plugincore/plugins/remove_lilo_plugin.py (+54/-0)
janitor/plugincore/testing/helpers.py (+68/-0)
janitor/plugincore/tests/data/alpha_plugin.py (+48/-0)
janitor/plugincore/tests/data/bravo_plugin.py (+48/-0)
janitor/plugincore/tests/data/charlie_plugin.py (+48/-0)
janitor/plugincore/tests/test_deb_plugin.py (+44/-0)
janitor/plugincore/tests/test_documentation.py (+93/-0)
janitor/plugincore/tests/test_dpkg_status_plugin.py (+45/-0)
janitor/plugincore/tests/test_file_cruft.py (+81/-0)
janitor/plugincore/tests/test_manager.py (+171/-0)
janitor/plugincore/tests/test_missing_package_cruft.py (+62/-0)
janitor/plugincore/tests/test_package_cruft.py (+62/-0)
po/POTFILES.in (+32/-21)
po/update-manager.pot (+607/-617)
setup.py (+8/-10)