Links with the same title are equal even if they point to different passages

Is your feature related to a problem? Please describe.

Links should be equal if both the text and reference it has, are equal. Even if the reference is null, this should be checked. This is to avoid two links which have the same text and are supposed to reference the same thing, but instead has null.

Describe the solution you'd like.

In the equals method, both the reference and text of the Link should be checked.