Added ability to store details of the uploaded GFS file in the command object.
Create helper service to help improve testability and potentially isolate low-level DB interaction.
Test can get a file by OID.
Add test to get file by filename.
Tidied.
Removed duplicate code.
Started making changes to allow testing and mocking of new features.
  - start using injection for context and services
  - start using helper for config
Add ID of created file to forwarded response after uploading.
Updated tag to:
  - allow thumbnail creation using filename or OID.
  - allow forwarding and chaining on controller success/error calls.