flake8: don't ignore E713 now that it's fixed E713 is "test for membership should be ‘not in’"

flake8: fix E713 style

flake8: fix E301 style

flake8: fix E111 style OFF BY ONE ERRORS ARE THE WORST

flake8: fix E222 style

flake8: fix E127 style

flake8: fix W391 style

tests: add flake8 check This test will hopefully help prevent style errors. To be determined: which errors / warnings to ignore?

flake8: add file for rules to ignore This will help prevent users that have an editor with flake8 capabilities from fixing linter errors for rules that are not wanted by the project. Initially, this ignore list includes everything in the project that violates pep8. I'll try to ween this list down to something a little more manageable.

init: guard _namemap with repo.topics (issue5351) This prevents reading extra data on all repo commits when there is no topic for a given name. _namemap is called a lot, and it is often called for commit shas -- which should pretty much never be names of topics...

init: cache repo.topics

stack: add warning about multiple heads This seems a good spot to nudge people toward reducing there head count.

stack: add some behind information This is the next useful thing after branch

stack: add some basic branch information In the same spirit as knowing the topic you are on, having some branch data seem useful (yet, this smell a bit like summary)