SolrCloud with custom package in dataimport

[stefan]

Hey,

Is it possible to reference a custom java class during the dataimport? The 
dataimport looks something like this:

```
<dataConfig>
    <dataSource
[...]
    />

    <document>
        <entity name="article"
                
processor="org.example.solr.articles.dataimport.ArticlesEntityProcessor"
                
transformer="TemplateTransformer,NumberFormatTransformer,org.example.solr.articles.dataimport.RatingRankTransformer,[...]"
```

I have tried using the plugin as `processor=plugin:org.example.solr.[...]` for 
the processor and the article. I did not succeed with that. 

Do we need to rewirte the plugin so i can replace the dataimport class? Using 
`class="plugin:org.apache.solr.handler.dataimport.DataImportHandler"` leads to 
a null pointer exception.

```
    <requestHandler name="/dataimport" 
class="org.apache.solr.handler.dataimport.DataImportHandler">
        <lst name="defaults">
            <str name="config">db-data-config.xml</str>
        </lst>
    </requestHandler>
```

Sadly I was unable to find any information on this topic.

Thanks for your help!