Add pipelining improvements

* Added lastCore and lastNode to performance data
* getInputTable behaves parallel to getOutputTable (Fixes #365)
* Add inRows/outRows to performance data
* PipeliningTableScan added
* Fix getActualTablePositions on nullptr poslist
* Add PipeliningHashBuild / PipelineMergeHashTables
* Implement integer LTEQ expression
Merge pull request #384 from kaihowl/pr/pipelining

Pr/pipelining
Merge branch 'master' into tests/sql