First crack at general comparison table

Lots of copy-pasta to be refactored.
Implemented duplicate button for queries
Merge pull request #259 from urbanairship/issue-258-duplicate-query-action

Implemented duplicate button for queries
Add bootstrap-datetimepicker component
Recent/custom range picker switching
Filling in rendering and event handlers
Comments
Set the 'until' field to now for now
dark mode support
Use UTC, quantize to 15-minute intervals
Handlers for setting from/until in custom range picker
Merge pull request #260 from urbanairship/issue-183-custom-daterange-picker

Issue 183 custom daterange picker
Improving layout of flot tooltip

Matches nvd3 more closely
Rewrote flot tooltip as a handlebars template
Moving flot legends to a separate container
Merge pull request #262 from urbanairship/flot-charts

Improvements to flot chart renderer
Don't assume UTC
Rename database record classes

* Renaming database record classes
`Dashboard` => `DashboardRecord`
`DashboardDef` => `DefinitionRecord`
`Tag` => `TagRecord`

Didn’t want them conflicting with the simpler names which will move to
the pure JSON model  classes in `tessera-client`

* Also added delete cascade so we’ll stop orphaning records in the
definition table. Oops!
Formatting
Use a decorator for model classes

Get rid of that big ugly if