Adds filebeat (log collector) to elasticsearch v6 docker block that 
collects Grafana logs.
Also adds a new elasticsearch v6 datasource and test dashboard 
thru provisioning.

* auto load

* update comments

* gofmt

* use preload from json

* fix formatting

* change general plugin loader to app

* Refactoring: Plugin preloading #15266

Add getQueryDisplayText() to DataSourceApi

* add some types on graph

* set some types in graph

* Fixed typings

* Unprovision dashboard in case of DisableDeletion = true

* Rename command struct

* Handle removed provision files

* Allow html in confirm-modal

* Do not show confirm button without onConfirm

* Show dialog on deleting provisioned dashboard

* Changed DeleteDashboard to DeleteProvisionedDashboard

* Remove unreachable return

* Add provisioned checks to API

* Remove filter func

* Fix and add tests for deleting dashboards

* Change delete confirm text

* Added and used pkg/errors for error wrapping

* show title in singlestat2

* show title in gauge

* use CSS class for emotion

* use emotion not scss

* Fix use of "monotonically" in explore documentation

* Fix use of "monotonically" in query hints and tests

Fixes #16378

* Wip: virtualize suggestions list

* Refactor: Separate components to different files

* Refactor: Made TypeaheadItem a FunctionComponent using emotion

* Refactor: Use theme to calculate width instead of hardcoded values

* Refactor: Calculate list height and item size

* Style: Adds labels to emotion classes

* Refactor: Flattens CompletionItems to one list

* Chore: merge yarn.lock

* Refactor: Adds documentation popup on the side

* Refactor: Makes position of TypeaheadInfo dynamic

* Refactor: Calculations moved to separate file

Fixes #16448

* aligned headings on profile, admin and configuration pages

* fixed snapshot

Fixes #16373

Replaces session storage in auth_proxy middleware with remote cache

Fixes #15161

This fixes an error that was thrown when one or several queries
was disabled using the mixed datasource.

Fixes #12977

* replaced colors for headingColor, link and linkDisabled with colors from grayscale, replaced colors for linkDisabled and linkHover with colors from grayscale, changed color for sha-modal-in-text to text-color-empahises

* fixed snapshot

Fixes #16439

Upgrades to webpack & css optimization caused changes
in production build that removed the left brand
gradient.

Fixes #16430

See https://github.com/grafana/grafana/pull/16200#issuecomment-479370356
Thanks @xlson

Ref #16200

* added new variables for height in theme, added height to gui button large, replaced add gicon with regular gicon, replaced + with gicon, changed button display to flex

* set fixed height to large button, removed xlarge button and replaced with large button

* removed button-mini and replaced with button-small, set fixed height to default button and button-small

* fixed padding for default and large button, fixed height for navbar button, fixed snapshots

* fixed padding and margin on navbar buttons

* gave special height to login btn-primary

* readded btn-mini class with same styling as btn-small and a deprecated notice

* fixed add panel widget buttons

Fixes #16359

LED cell width needs to be integers

Override decimals did not fully override auto scaling logic

Fixes #16068