fixup! No longer hide unseen content as part of Getty ingest
Warn about duplicate Getty items
Keep track of expected Getty item count and stop if exceeded

- This is because their pagination is broken.
- The expected count is returned in a clumsy hackish way due to:
    - laziness
    - lack of tuple support
    - hopefully-temporary nature of the hack
Merge pull request #595 from atlasapi/getty-paranoia

Simple diagnostics for Getty ingest