Hyperlinked PK optimization. Closes #1872.
Optimizations play nicely with select_related, prefetch_related
Drop get_iterable()
Move comment
Merge pull request #2242 from tomchristie/hyperlinked-pk-optimization

Hyperlinked PK optimization.
Release notes for 3.0.1
Version 3.0.1
Field->ReadOnlyField in tutorial docs
Release note corrections
Add links to the issue id.
Add full stop to the release note items.
Add link to the issues
Fix the milestone link
Fix the milestone link again.
Better link representation for the issues.
Fix the ghost backtick.
Merge pull request #2251 from linovia/version/3.0.1

Release notes & version 3.0.1