restores dry mode output to user
rescue Sequel DatabaseErrors when importing
ensure that each importer instance uses a closed set of record proxies
validate json records while creating batch
a few minor and cosmetic changes
write tests for import queue / cache and remove unused code
Have the batch import endpoint manage its own transactions based on which database is running.

Explicitly roll back the transaction on error.
WIP Demo of columns in the tree
WIP add instance types to the tree
let record proxies collect data and create objects later
refactor csv importer
remove path option from accessions config
create a digital object csv for testing
complete digital object mappings
add test for tracer digital object csv
Merge pull request #473 from hudmol/batch-import-transactions

Have the batch import endpoint manage its own transactions
resolve conflicts
Have the public interface retry if it can't connect to the backend.
Show all components by default in Resource records in the public view.
Move helper methods into 'private'