Add no auto update comment for overriding

[pnadolny13]

Sometimes it easier to make changes to the hub definitions manually vs fixing the underlying tap. In this case sometimes the hub update code reverts the manual changes. We should have a way to tell the code to not update that attribute even if it has changes.

Similar to a # noqa comment for linting we could add a comment to the yaml to flag manual overrides.

[pnadolny13]

Ruamel supports preserving comments but we clobber them when we retrieve the settings from the about output. We should instead iterate the output and update only settings that don't have the ignore comment included for now.