* feat(explore): export csv data pivoted for Pivot Table
* Implement dropdown with download csv options
* Change label to "Original"
* Add tests
* Add form data to query context
* Add form data to query context generator
* Explicitly make form_data optional
* feat: add support for generic series limit
* refine series_columns logic
* update docs
* bump superset-ui
* add note to UPDATING.md
* remove default value for timeseries_limit
* rebase master and resolve conflicts
* pylint to makefile
* fix crash when pivot operator
* fix comments
* add precision argument
* query test
* wip
* fix ut
* rename
* set time_offsets to cache key
wip
* refactor get_df_payload
wip
* extra query cache
* cache ut
* normalize df
* fix timeoffset
* fix ut
* make cache key logging sense
* resolve conflicts
* backend follow up iteration 1
wip
* rolling window type
* rebase master
* py lint and minor follow ups
* pylintrc