More robust mbqlCanonicalize, just in case

New docs for 0.18.1

Revert to using _.sortBy which actually sorts numbers correctly ಠ_ಠ

Cleanup and fix FieldName

Fix mongo type information for native queries 

Don't apply magic sorting to BigQuery native queries 

Fix fetching DB type on Heroku 

tighten up some stray debug logging.

Documentation for 0.18 

Don't detect D-M as D-M-M which causes multiseries header to be shown

Fix issue with cursor moving to end of native editor

Add query_hash column and indexes, use for /api/dataset/duration endp…

Ensure the 'Done' button doesn't appear

Avoid divide-by-zero when no query executions exist, and ensure we use the exact dataset query when fetching expected duration