Add support to render values of multiple queries in the same table

Avoid ID validation before provisioning dashboards

If the cookies are specified in the keepCookies property then they
should not be deleted from proxied requests for data sources

The ds proxy strips out cookies. Cookie names specified in
this field will not be stripped out. This is the frontend
change only.

Attempting to provision grafana using a previously exported
JSON dashboard with the ID field already set, might result in an error.
In fact, Grafana might believe that a dashboard with that
given ID already exists in the database, throwing an error if it doesn't.
(see pkg/services/sqlstore/dashboard.go#L32)

The dashboard provisioner should set the dashboard id to zero in order to
avoid this behaviour inducing the dashboard to be written to the DB
without ID validation.

* Thib17-master:
  alertmanager: endAt should only be used if we have the correct value
  alertmanager: code style
  alerting: reduce log level for notifiers
  Alertmanager notifier: add "metric" labels if no tags
  Alertmanager notifier: make it match the new notifier interface
  support alertmanager

Signed-off-by: Thibault Chataigner <t.chataigner@criteo.com>

Signed-off-by: Thibault Chataigner <t.chataigner@criteo.com>

* removes readonly editor role

* adds viewersCanEdit setting

This enable you to allow viewers to edit/inspect
dashboards in grafana in their own browser without
allowing them to save dashboards

* remove read only editor option from all dropdowns

* migrates all read only viewers to viewers

* docs: replace readOnlyEditor with viewersCanEdit

closes #9318

* Thib17-master:
  removes verbose logging
  Add a per-notifier ShouldNotify()

This way we are able to edit notification behavior per notifier.
This would be usefull to let some notifiers send notifications,
even when the state doesn't change, or with custom condition.

Signed-off-by: Thibault Chataigner <t.chataigner@criteo.com>

graphite: minor fix for PR #10142 the query was being sent for every segmen t you selected before you completed the metric path

Fixes bug in cloudwatch regarding credentials

* moved unique value naming to datasource (credit: @bergquist)
* merge rows based on same column-values and empty values
* expanded tests