Move the functions inside the distributor and import them
where needed. This reduces duplication and makes it possible
for flake8 to detect when the functions aren't used in a
given file.
If rejecting a remote invite fails with an error response don't fail
the entire request; instead mark the invite as locally rejected.
This fixes the bug where users can get stuck invites which they can
neither accept nor reject.
pycharm supports them so there is no need to use the other format.
Might as well convert the existing strings to reduce the risk of
people accidentally cargo culting the wrong doc string format.
