Changelog: 6.4.0-beta2 release (#19380)

* changelog: add 6.4.0-beta2 release

* add back toolkit changes to main changelog

CHANGELOG.md

 # 6.4.0 (unreleased)
 
+# 6.4.0-beta2 (2019-09-25)
+
+### Features / Enhancements
+* **Azure Monitor**: Remove support for cross resource queries (#19115)". [#19346](https://github.com/grafana/grafana/pull/19346), [@sunker](https://github.com/sunker)
+* **Docker**: Upgrade packages to resolve reported vulnerabilities. [#19188](https://github.com/grafana/grafana/pull/19188), [@marefr](https://github.com/marefr)
+* **Graphite**: Time range expansion reduced from 1 minute to 1 second. [#19246](https://github.com/grafana/grafana/pull/19246), [@torkelo](https://github.com/torkelo)
+* **grafana/toolkit**: Add plugin creation task. [#19207](https://github.com/grafana/grafana/pull/19207), [@dprokop](https://github.com/dprokop)
+
+### Bug Fixes
+* **Alerting**: Prevents creating alerts from unsupported queries. [#19250](https://github.com/grafana/grafana/pull/19250), [@hugohaggmark](https://github.com/hugohaggmark)
+* **Alerting**: Truncate PagerDuty summary when greater than 1024 characters. [#18730](https://github.com/grafana/grafana/pull/18730), [@nvllsvm](https://github.com/nvllsvm)
+* **Cloudwatch**: Fix autocomplete for Gamelift dimensions. [#19146](https://github.com/grafana/grafana/pull/19146), [@kevinpz](https://github.com/kevinpz)
+* **Dashboard**: Fix export for sharing when panels use default data source. [#19315](https://github.com/grafana/grafana/pull/19315), [@torkelo](https://github.com/torkelo)
+* **Database**: Rewrite system statistics query to perform better. [#19178](https://github.com/grafana/grafana/pull/19178), [@papagian](https://github.com/papagian)
+* **Gauge/BarGauge**: Fix issue with [object Object] in titles  . [#19217](https://github.com/grafana/grafana/pull/19217), [@ryantxu](https://github.com/ryantxu)
+* **MSSQL**: Revert usage of new connectionstring format introduced by #18384. [#19203](https://github.com/grafana/grafana/pull/19203), [@marefr](https://github.com/marefr)
+* **Multi-LDAP**: Do not fail-fast on invalid credentials. [#19261](https://github.com/grafana/grafana/pull/19261), [@gotjosh](https://github.com/gotjosh)
+* **MySQL, Postgres, MSSQL**: Fix validating query with template variables in alert . [#19237](https://github.com/grafana/grafana/pull/19237), [@marefr](https://github.com/marefr)
+* **MySQL, Postgres**: Update raw sql when query builder updates. [#19209](https://github.com/grafana/grafana/pull/19209), [@marefr](https://github.com/marefr)
+* **MySQL**: Limit datasource error details returned from the backend. [#19373](https://github.com/grafana/grafana/pull/19373), [@marefr](https://github.com/marefr)
+
 # 6.4.0-beta1 (2019-09-17)
 
 ### Features / Enhancements

packages/grafana-toolkit/CHANGELOG.md

 # 6.4.0 (unreleased)
 
+# 6.4.0-beta2 (2019-09-25)
+
+### Features / Enhancements
+* **grafana/toolkit**: Add plugin creation task. [#19207](https://github.com/grafana/grafana/pull/19207), [@dprokop](https://github.com/dprokop)
+
 # 6.4.0-beta1 (2019-09-17)
 First release, see [Readme](https://github.com/grafana/grafana/blob/v6.4.0-beta1/packages/grafana-toolkit/README.md) for details.