test(link handler): fix test, since the handler now throws on error
feat(partial-names): add removeDoc method
feat(jsdoc/compute-paths): add new processor

This was extracted out from the id tag definition in the ngdoc package.
It also now allows us to config the partials folder (now called
config.rendering.contentsFolder)
feat(PartialNames): getLink disambiguates docs by area

If there are more than one doc that match a name then the getLink method
fails saying that the name is ambiguous.
Now, if you pass in the current document to getLink then it will first
try to filter out, from the ambiguous docs, those that are in areas
other than the current doc. If this leaves only one doc then that is
returned successfully.
feat(jsdoc tags): improve jsdoc tag coverage

Add in some missing tags and note that name is not actually a required
tag. In some situations it would be inferred from the code position.
feat(tagParser): only ignore tags that are defined with ignore property

Previously any unknown tag was ignored.  This left potential for badly
spelled tags to be missed, leading to broken documentation.
Now, all unknown tags cause warning to be shown and only tags that have
a definition with the ignored property set to true will actually be
ignored.

BREAKING CHANGE: If you relied on undefined tags being quietly ignored
your processing will now fail.  You should add new tag defintions for
all tags that you wish to ignore of the form:

```
{ name: 'tag-to-ignore', ignore: true }
```
refact(partial-name processor): move adding docs to own processor

Before the api-docs processor was adding docs to the partialNames object.
But this was not a cohesive feature of api-docs. This commit moves that
work into its own processor.
fix(filter-ngdocs processor): run before tags are extracted

Otherwise bad comments get through and fail in the tag-extractor.
refact(ngdoc/id tag def): move functionality to its own doc processor

Tag-defs should not do document processing.  The id tag-def was doing
too much work. So some of it has moved into the compute-id processor
and other bits into the api-docs processor.
fix(compute-paths): ensure contentsFolder is applied correctly