SignificantText aggregation has include/exclude logic back to front

[markharwood]

Include clauses exclude and Exclude clauses include.

From the SignificantTextAggregatorFactory:

                        if (includeExclude != null && includeExclude.accept(bytes) ) {
                            continue;
                        }

This should instead check accept(bytes) == false

[elasticmachine]

Pinging @elastic/es-analytics-geo (:Analytics/Aggregations)