Download csv measurements template.

- Don't show csv tab when user not permitted or when no devices present.
Merge pull request #91 from MastodonC/feature/csv-template-download

Download csv measurements template.
GET entities as tall CSVs
POST entities as tall CSVs
make sure id is not part of an update SET query
PUT entities as tall CSVs
Merge pull request #93 from MastodonC/feature/entity_contextual_csv

Feature/entity contextual csv
Add user editable keys to device API.
Merge pull request #94 from MastodonC/feature/devices-api-fix

Don't allow the user to update internal data.
Ignore user_metadata for synthetic readings.
Merge pull request #95 from MastodonC/feature/synthetic-readings-fix

Ignore user_metadata for synthetic readings.
Bump alia and thus the datastax driver.
Merge pull request #96 from MastodonC/feature/alia-update

Bump alia and thus the datastax driver.
Smaller page size for batches.

To avoid write timeouts we're experiencing.
Merge pull request #97 from MastodonC/feature/measurement-smaller-pages

Smaller page size for batches.
Add device / sensor validation to csv-upload.

prismatic schema validation for devices and sensors. data level authorization.
make page size for measurements 10.

see #97
Make update strip out pks when necessary.
Fix id confusions.
Merge pull request #84 from MastodonC/feature/csv-upload-validation

Some validation on CSV upload