Currently no upgrades needed by default.
Use weak identity map to stop indexer process growing unboundedly
Item and key caching.
LRUCache for embedding too
Fix caching so it is properly cleared between top level requests.
Split up code of embed to make cache logic clearer.
manager.stack[0] *is* the top level request
Increase cache capacity.
Python package versions update.
Merge pull request #182 from ENCODE-DCC/python-update

Python package versions update.
Merge pull request #183 from ENCODE-DCC/better-caching

Better caching
Adjusted to avoid line-wrap of most labels at zoom, etc.
Don't eager as it leads to memory errors; load in batches.
Merge pull request #184 from ENCODE-DCC/dd-dt-alignment-fix-577

Adjusted to avoid line-wrap of most labels at zoom, etc.
Don't try to be clever with eager loading.
Don't eager linked objects when getting by unique key to save memory.
Fix execute counts in tests to reflect new behaviour.
Merge branch 'master' into database-memory-usage
Merge pull request #185 from ENCODE-DCC/database-memory-usage

Database memory usage
Merge branch 'master' into dbxref_restructure-817