Updated sizes for HashSetBenchmark
Removed 'add' and 'remove' from HashSetBenchmark as they didn't work anyway
Added saving to file to the app for extracting identifiers from Scala source files
Rewritten HashSetBenchmark
Added "add", "remove" and string data to HashSetBenchmark
Changed HashSetBenchmark executor to SeparateJvmsExecutor
Changed HashSetBenchmark aggregator from 'min' to 'average'