(Bug)fixes related to table strategy

Hi Jorg,

I have three fixes ready in msimons/elasticsearch-river-jdbc.

1) The acknowlegdment of river items didn't work. I have fixed this by calling the acknowlegdment method on the RiverSource from the afterBulk method in the RiverMouth. Besides i fixed the creation of the table test rivertables.

2) The source_operation (delete,create,index) from a river item wasn't propagated to the StructuredObject optype.Here by the document was indexed instead of deleted. I extended a existing test to cover this situation.

3) The properties "source_timestamp", "source_operation" (rivertable) and …
pseudocolums "ID","INDEX","TYPE" and "PARENT" are now not unnecessary
indexed as source properties. I added a test to cover the TableValueListener and modified the SimpleValueTest for this situation.