Coerce SB arc-name fields

[ulrichhave]

Please consider coercing the types of the SB arc-name fields:

<field name="arc_job" type="string" indexed="true" stored="true" multiValued="false" docValues="true"/>      

please rename/copy to job_id and coerce to integer,

<field name="arc_harvest" type="string" indexed="true" stored="true" multiValued="false"/>   

please rename/copy to harvest_id and coerce to integer,

<field name="arc_harvesttime" type="string" indexed="true" stored="true" multiValued="false"/>

coerce to tdate.

This enhancement will allow range queries.