MXS-1940 Turn cache filter non-experimental

Also change the following defaults:

- "selects": Was "verify_cacheable", is now "assume_cacheable"
- "cached_data": Was "shared", is now "thread_specific"

Documentation/Release-Notes/MaxScale-2.2.11-Release-Notes.md

@@ -0,0 +1,44 @@
+# MariaDB MaxScale 2.2.11 Release Notes -- 2018-06
+
+Release 2.2.11 is a GA release.
+
+This document describes the changes in release 2.2.11, when compared to
+release 2.2.10.
+
+For any problems you encounter, please consider submitting a bug
+report at [Jira](https://jira.mariadb.org).
+
+## Changed Features
+
+### Cache
+
+The cache filter is no longer marked as being experimental. The default
+value for `cached_data` been changed from `shared` to `thread_specific`,
+and the default value for `selects` has been changed from `verify_cacheable`
+to `assume_cacheable`.
+Please consult the
+[cache documentation](../Filters/Cache.md)
+for details.
+
+## Bug fixes
+
+
+## Known Issues and Limitations
+
+There are some limitations and known issues within this version of MaxScale.
+For more information, please refer to the [Limitations](../About/Limitations.md) document.
+
+## Packaging
+
+RPM and Debian packages are provided for the Linux distributions supported
+by MariaDB Enterprise.
+
+Packages can be downloaded [here](https://mariadb.com/downloads/mariadb-tx/maxscale).
+
+## Source Code
+
+The source code of MaxScale is tagged at GitHub with a tag, which is identical
+with the version of MaxScale. For instance, the tag of version X.Y.Z of MaxScale
+is X.Y.Z. Further, *master* always refers to the latest released non-beta version.
+
+The source code is available [here](https://github.com/mariadb-corporation/MaxScale).