[frontend] Timeout on backend task response after 15s
[frontend] Handle timeouts on backend calls
[frontend] Fully promisify all the backend task calls
[backend] Handle missing parameters in PUT /works/NNN
Docstrings for tasks.py
Document returned errors, and tighten up some related error handling
Merge pull request #11 from commonsmachinery/tasks-documentation

Docstrings for tasks.py
Use context manager to handle storage syncing
Merge pull request #12 from commonsmachinery/workers-concurrency

Use context managers to handle storage syncing
Merge branch 'master' into frontend-call-wrapper
Merge pull request #13 from commonsmachinery/frontend-call-wrapper

Frontend call wrapper
[frontend] Translate about:resource in the RDF/JSON metadata (not cachedExternalMetadata)
[frontend] get methods for post metadata and CEM
[backend] Use sqlite by default in local/dev environment
[backend] Don't use BACKEND_STORE_DIR, since we look for database in cwd when running locally
Post update methods in backend and rest.js
[frontend] Correct URL for PUT post.
[backend] Fix post deletion.
Update tests and README
[backend] Use sqlite store by default and remove hashes