Validate that query memory usage or spilling has not regressed in 2.5

We want to validate that memory usage or spilling has not increased due to IMPALA-1305 and various other changes. We should use concurrent_select.py to find the new memory limits to complete with and without spilling:

• On local scale factor 1 data sets: TPC-H, TPC-H nested, TPC-DS
• On local larger scale factor data sets
• On larger cluster data sets