PDI-10704 - Get rows from result step does not pass rows when
transformation is executed in cluster mode
[PDI-5298] Samples need some fixing [Delete duplicate unusable package-res from engine]
[PDI-5298] Samples need some fixing
[PDI-5298] Samples need some fixing [PDI-11454]
[PDI-11252] Connection JNDI access type is stored as ", " in ktrs rather than "JNDI"
[PDI-5298] Samples need some fixing [PDI-11252]
Merge pull request #417 from stepanovdg/PDI-5298

PDI-5298/PDI-11367 Samples need some fixing
Merge pull request #381 from dbahdano/PDI-10704

The transformation executed on cluster could get rows from previous trans/jobs since previous result hasn't been set. Do it in this commit.
PDI-10250, PDI-6960 - ["Group by" step - Minimum aggregation doesn't work], [Group by and Memory group by ignores NULL values ("sum" aggregation)]

[PDI-10250]
Fix provided.
2 new variables introduced: KETTLE_AGGREGATION_MIN_NULL_IS_VALUED and
KETTLE_AGGREGATION_ALL_NULLS_ARE_ZERO.
junits added.

[PDI-6960]
Do not fill with 0 by default new aggregations.
If aggregation still null - this will return null or 0 depends on 'KETTLE_AGGREGATION_ALL_NULLS_ARE_ZERO' variable.
Junits added.
PDI-11530 - "Memory Group by" step - Minimum aggregation doesn't work

fix added.
junit tests added.
PDI-9662, PDI-11597 - [Denormalizer step: Minimum aggregation doesnt' work], [Denormalizer step: 100 + null = null]

[PDI-9662]
fix.
Avoid newGroup() intialize min with null.
Added support of new varibles to handle aggregation null-cases.

[PDI-11597]
fix.
replace ValueDataUtil.plus(...) call with sum(...) to handle nulls
properly.