AutoResize of columns in ItemListView reduces GUI update performance massively

[swagner]

In r9755 of #1421 a call to AdjustListViewColumnSizes was added to Item_ToStringChanged in ItemListView, ItemCollectionView and ItemArrayView. AdjustListViewColumnChanges then calls AutoResize on all column headers. This change reduces GUI update performance massively.

Runtime tests with changes of r9755 (quad-core CPU):

• single GA/TSP sample with SequentialEngine: 10 sec
• single GA/TSP sample with SequentialEngine after showing all algorithm tabs once: 25 sec
• 4 GA/TSP samples with SequentialEngine in parallel: 65 sec (each algorithm)
• single GA/TSP sample in an experiment without showing algorithm view: 4 sec
• 4 GA/TSP samples in an experiment with 4 workers without showing algorithm views: 5,5 sec (each algorithm)

Runtime tests without changes of r9755 (quad-core CPU):

• single GA/TSP sample with SequentialEngine: 5 sec
• single GA/TSP sample with SequentialEngine after showing all algorithm tabs once: 5 sec
• 4 GA/TSP samples with SequentialEngine in parallel: 7 sec (each algorithm)
• single GA/TSP sample in an experiment without showing algorithm view: 4 sec
• 4 GA/TSP samples in an experiment with 4 workers without showing algorithm views: 5,5 sec (each algorithm)