Update version to 6.6.

Adds a new setting disable_admin_user and when true the default 
admin user will not be created when Grafana starts for the first 
time (or no users exists in the system).

Closes #19038

* fixes according to feedback

* additions to config and docs

* metric tank meta

* add metric tank info

* fixed info box

* process meta

* attach metrictank meta to response

* remove extra logging

* response is now DataFrame

* Minor refactoring and renaming of the prop

* Graphite: minor fixes

* add dependencies to support oracle plugin in alpine

* fix typo

* add generated docker image for PR to artifacts to make testing easier

* update path to artifact

* debug path to artifact

* debug path to artifact

* debug path to artifact

* fix ld.so.cache conflict

* only add glibc-compat for x86_64 builds

* do not store docker image in artifacts

* fix missing fi

* add basic components

* adding onchange handler for Prom settings

* move options outside component

* reorder imports

* Add missing setting

* e2eTests: Adds cleanup of created datasource and dashboard

* Chore: Fixes Prettier error

* Tests: Updates snapshots

* Panel: fix the default value of thresholds cannot be modified in Gauge panel

* Panel: fix the default value of thresholds cannot be modified in Gauge panel

* AuthProxy: Can now login with auth proxy and get a login token

* added unit tests

* renamed setting and updated docs

* AuthProxy: minor tweak

* Fixed tests and namings

* spellfix

* fix

* remove unused setting, probably from merge conflict

* fix

* Build: Add /Dockerfile.ubuntu
* Build: Add packaging/docker/Dockerfile.ubuntu
* Build: Add grafana-docker-ubuntu-pr CircleCI job
* Build: Add CircleCI jobs for building master/release Ubuntu based Docker images

The arching goal of this commit is to enable single user
synchronisation with LDAP. Also, it included minor fixes of style,
error messages and minor bug fixing.

The changes are:

- bug: The `multildap` package has its own errors when the user is
  not found. We fixed the conditional branch on this error by asserting
on the `multildap` errors as opposed to the `ldap` one

- bug: The previous interface usage of `RevokeAllUserTokens` did not
  work as expected. This replaces the manual injection of the service by
leveraging the service injected as part of the `server` struct.

- chore: Better error messages around not finding the user in LDAP.

- fix: Enable the single sync button and disable it when we receive an
  error from LDAP. Please note, that you can enable it by dispatching
the error. This allows you to try again without having to reload the
page.

- fix: Move the sync info to the top, then move the sync button above
  that information and clearfix to have more harmony with the UI.

* Fix: Adds Explore menuitem to React Panels
Fixes #19865

* Refactor: Adds CMD|CTRL+click to Explore menu item

* Elasticsearch: Support rendering in logs panel

- add "Logs" metric query type so panels can inform the datasource that
the query is a logs query
- datasource modifies target when metric query type `logs` is detected
- then existing log result processeing paths are followed

* Fix failing test, number of agg types changed

* Notifications: Add alert_state to the kafka message Fixes #11401

* Renamed ttl config in code to be more consistent with behaviour
* Introduced new setting `sync_ttl` in .ini file
* Keeping the old setting `ldap_sync_ttl` in the .ini file as fallback and compatibility.

Provisioning of dashboards now always overwrite existing ones and does not look at the configuration `allowUiUpdates` anymore

* Adding grafana plugin version info

It was unclear if one can specify the plugin version to the environment variable. It is possible and works fine. Added it to the plugin information.

* Update typo docs/sources/installation/docker.md

* Applied all comments

Moved the information to make it more readable, fixed typos and added missing punctuation.

* Rewording and better example

More feedback, added example text. Did not manage to get newline for the example.

* added the missing space

* query mixed

* query mixed

* batch queries

* check that the values only have 3 rows at the *end* as well

* don't explode when missing logo

* add path to a real icon

* LDAP: Interpolate env variable expressions in ldap.toml file

* Removed comment

assumption is that msi MAX_PATH is effectively 130 (260/2) for the full path of the filename (Dir + filename), and this causes error LGHT0103 : The system cannot find the file in the msi build.

* Explore: fixes toolbars datasource selector and date picker responsiveness

* Explore: updates grafana UI time picker component - adds a class on long date

* Explore: updates styles for responsive long date without split

* Explore: adds styles for responsive time picker with long date during split

* Explore: updates long datetime detector to isDateTime, renames isAbsolute to hasAbsolute

* Explore: updates datasource responsiveness

* Explore: moves time picker styles

* Explore: updates datasource picker and select component responsiveness

* Explore: updates data source picker

* Explore: updates explore toolbar to use container width

* Explore: updates styles for datasource picker

* Explore: updates Grafana UI elements - select and single value with an ability to hide text

* Explore: updates time picker styles

* Explore: updates datasource select and date picker

* Explore: updates toolbar elements margin

* Explore: updates toolbar elements split breakpoints

* Explore: updates datasource picker label length with substrings

* Explore: updates the datasource picker label length

* Explore: removes refresh picker hide media query

* Explore: updates refresh picker style query to use xs breakpoint

* Fix: Prevents crash when table receives mixed data formats
Fixes #20075

* Tests: Adds tests for data format reducers

* Refactor: Updates after PR comments

* Refactor: Missed a couple of places where filtering was needed

Adds a config section with derived fields which is a config that allows you to create a new field based on a regex matcher run on a log message create DataLink to it which is the clickable in the log detail.

As discussed in a UX feedback session, it's annoying that queries are
automatically executed in Explore. This change adds props to override
the blur behavior.

- add `onBlur` to Explore query field props
- Explore's query row will pass down an empty function for onBlur to the
query fields
- pass onBlur through to the QueryField component for Loki and
Prometheus
- add test to QueryField to make sure if onBlur is specified, the
onRunQuery is not executed