Add endpoints for adding/deleting/reading movies.

Documentation and tests also included.

Also cleaned up .pylintrc a bit, adding reasons as to why we ignore
some warnings, and ignoring a couple extra.

Note that we for now don't have any CSRF protection towards the API,
so anyone from anywhere can post and delete content. I guess we'll
add protection later on, shouldn't be too hard once we know how we
want to restrict access.