We were already doing so for debates and investments.
We probably never noticed because this is an edge case that requires
enabling a feature, people adding comments, and then disabling the
feature.
It could be argued that seeing which proposals a user follows is a good
indicator of which proposals a user has supported, since we're
automatically creating follows for supported proposals since commit
74fbde09f. So now, we're extending the `public_interests` funcionality,
so it only shows elements users are following if they've enabled it.
This is an improvement over using the `public_activity` attribute in two
ways:
* The `public_interests` attribute is disabled by default, so by default
other users won't be able to see what a user is following
* Who has created proposals/debates/investments/comments is public
information, while who is following which elements is not; so enabling
`public_activity` shouldn't imply potentially private information should
be displayed as well
We've considered removing the `public_interests` attribute completely
and just hiding the "following" page for everyone except its owner, but
keeping it provides more compatibility with existing installations.
