* fix label handling

* SEARCH() results could have multiple namespace, remove from legend

* divide GetMetricStatistics related code

* divide GetMetricData related code

* divide parseGetMetricDataResponse()

* divide parseGetMetricDataQuery()

* divide test code

* add test for GetMetricData

* add test for GetMetricData parse response

* fix bug of terminating gap

* fix gofmt

This is basically implementation of the https://github.com/grafana/grafana/issues/8900#issuecomment-435437167
points, except for the type conversion bit.

I tried to implement idea mentioned in cockroachdb ticket (see below).
And it is possible, but it complicates things as lot - not only we have to
have 4 SQL statements instead of one, but we would have to copy the column
structure as well - PK, FG, indexes and stuff, plus there will
be additional downtime with this approach.

So idea for this pull is to prepare our SQL as much as possible, so when
cockroachdb will add support for full type conversions, we could easilly add
support for it as well.

* Add `CASCADE` to `DROP INDEX` statement

* Make string conversions explicit

Thanks @Luit

Ref #8900
Ref cockroach/cockroach#9851

* app pages

* app pages

* workign example

* started alpha support

* bump controller limit

* bump controller limit

* existing plugin pages work again

* save Plugin in cache

* remove AppPage wip

Progress: #14714

* Store passwords in secureJsonData

* Revert unnecessary refactors

* Fix for nil jsonSecureData value

* Remove copied encryption code from migration

* Fix wrong field reference

* Remove migration and provisioning changes

* Use password getters in datasource proxy

* Refactor password handling in datasource configs

* Add provisioning warnings

* Update documentation

* Remove migration command, moved to separate PR

* Remove unused code

* Set the upgrade version

* Remove unused code

* Remove double reference

* Dev: more dev dashboards and structure

* Moving gdev dashboards around into folders and aligning tags

fix govet issue in golang 1.12.4

Alerting: Adjust label for send on all alerts to default 

Initial alpha datasource that saves data directly in a panel or in the shared datasource configs.

Temporarily expose getBackendSrv while we figure out a long term solution.  This will unblock developing some more complex react external plugins.

For react panels the scopedVars did not contain the built in __interval and __interval_ms
variables.

Fixes #16546

Progress: #14714

Closes #15889

CloudWatch: Fix template variable issues 

* fix cloudwatch color order

* fix test

* use for-of

* app pages

* app pages

* workign example

* started alpha support

* remove app stuff

* show warning on alpha/beta panels

* put app back on plugin file

* fix go

* add enum for PluginType and PluginIncludeType

* Refactoring and moving settings to plugins section

fixes #16529

This reverts commit 44b36502.

moved page-action-bar to top and put header inside it, removed </input> to be able to run prettier

While converting this to React we missed subscribing to errors

Fixed #16512

fixes go vet issue that 1.12.3 detects 

Fixes #16501

Fixes #16507

Markdown formatting in VS Code converts from asterisks to underscores but this can be incorrect
in a case like _label_names()_. This fix escapes the underscores that should be kept.

Fixes: #16490

Fixes: #16485

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