Differentiate pending/old revisions and default translations

Problem/Motivation

Thanks for a fantastically useful module! It's being used on a multi-lingual site where people can't tell the difference between a reference in an old revision from one within a default translated revision. From their point of view it's critical to know if something's referenced in a default revision whatever the language.

Steps to reproduce

1. Create a node called Target.
2. Create a node called Test 1 in English and reference Target in the body field.
3. Update Test 1 removing the link to Target and creating a new revision.
4. Create a node called Test 2 in English with an empty body.
5. Translate Test 2 into French, adding a reference to Target in the body field.
6. Look at the entity usage for Target

The entity usage page doesn't let you differentiate between the usage in the default French revision vs the old English revision: it just says Translations or previous revisions.

Proposed resolution

I can see a number of ways of displaying the information. I was thinking we could separate out default, pending and old revisions into separate lines in the same table cell. If more than one language is involved, the languages can be listed, but if not try to leave the wording the same.

Remaining tasks

User interface changes

See the description and image above, this is purely a UI change to the listing page.

API changes

Data model changes