API doc fix
Merge pull request #443 from edx/markhoeber/doc-fix

Markhoeber/doc fix
Remove "limited release" messages and advanced component info
Merge pull request #448 from edx/sylvia/docs/AdvProb-ORA2

Remove "limited release" messages and advanced component info
Provide default settings for dependency injection
Merge pull request #451 from edx/will/ai-internal-settings

Default settings for dependency injection
Merge pull request #452 from edx/ai-grading

Ai grading
Fallback to file-based cache for classifier data
Add info-level logging for cache hits/misses