Bump version to 28.1
Merge pull request #1314 from reciprocity/feature/version-sprint-28.1

Bump version to 28.1
Fixes for when <resource>.id == 0

* On client side, these objects would not be cached, and stubs would not
  work properly
* On server side, the objects would have invalid `href`, `selfLink`, and
  `viewLink` values and missing `Location` headers
Merge pull request #1318 from reciprocity/feature/fix-for-id-of-0

Fixes for when <resource>.id == 0
Restrict `Edit` link visibility correctly
Check for null context along with null context id.
Merge pull request #1320 from reciprocity/feature/audit-context-null-check

Check for null context along with null context id.
Bump version to s28.2
Merge pull request #1321 from reciprocity/feature/version-sprint-28.2

Bump version to s28.2
Merge pull request #1319 from reciprocity/feature/fix-edit-link-permissions

Restrict `Edit` link visibility correctly
Merge remote-tracking branch 'origin/release/0.9a28' into develop