This change neccesitated changing the behavior or the
`filter_since_tag`. Since we want our compare links to include the since
tag, we need to keep that tag in the filtered list. Instead, we detect
that the tag is the since tag and filter it out. This will prevent the
since_tag header from being duplicated when pulling from a base.
The same goes for the first tag listed in between_tags. We don't want an
empty section header for this.
Signed-off-by: Tom Duffield <tom@chef.io>
d6c26ef4a9