ElasticSearch plugin is limited to 256 bytes for FULL TEXT INDEX search

[wdroste]

Introduction
According to the documentation, there's a limitation on FULL TEXT INDEX of 256 bytes which is the same as the existing index. However as user I want to index long text like description, comment, or 'issue' which is inline with something like ElasticSearch where the text is much longer than 256 and is tokenized for FULL TEXT searching.

Contents
FULL TEXT index should just be a pass through to the plugin, truncating it before it gets there limits its functionality.