v7.0-beta.69

* Improve handling of duplicates in reference data loads.

* Improve error messages for reference loading failures.

* Issue **#1936** : Fix reference data loaded not loading string values > 1000btyes.

* Improve PooledByteBufferOutputStream.

* Issue **#1807** : Remove need for Manage Nodes permission in order to list nodes (needed to manage volumes).

* Issue **#1806** : Remove need for Manage Nodes permission in order to list nodes (needed to manage tasks).

* Issue **#1925** : Fixed logging error that was happening on search.

* Issue **#1921** : Fixed problem with the dashboard text pane not migrating properly to the new special stream id and event id fields.

* Issue **#1910** : Fixed issue preventing display of table data where a table had duplicate column names.

* Issue **#1919** : Fixed issue that was preventing dashboard tabs from being closed.

* Removed rxjava.

* Issue **#1919** : Dashboards now prevent tabs being closed from the close button if some nested tabs on the same pane are hidden.

* Issue **#1915** : Multiple statistic searches on a dashboard are now executed in parallel.

* Issue **#1915** : Fixed task context user identity for statistics searches.

* Issue **#1915** : Fixed task context for statistics searches.

* Merged external expression and query libraries into the source code and added Kryo serialisation to search results.

* Issue **#1910** : Duplicate fields in dashboard tables are now avoided by adding a numeric suffix to the field name when adding a duplicate.

* Issue **#1918** : Text presenter was losing track of stream and event id fields when settings were changed.

* Issue **#1906** : Added info about queue sizes to extraction task.

* Issue **#1906** : Made changes to allow early termination of searches if we have enough data.

* Issue **#1906** : Fixed node task nesting.

* Issue **#1906** : The maximum size of the stream event map is now configurable with the `stroom.search.extraction.maxStreamEventMapSize` property.

* Issue **#1906** : Improved the way search extractions events are grouped so we can extract more events per stream and therefore improve performance.

* Issue **#1907** : Fixed NPE.