Added IntIntMapTest and minor improvments

Added new IntIntMapTest to compare values with radargun benchmark.

Added new methods to KeyUtils.java for Integer keys.

Added new method addOperationRemainingProbability() to OperationSelector.java to add an operation which consumes the remaining probability.

Cleanup of bash scripts: update-stabilizer makes now use of $STABILIZER_HOME if set and uses maven to determine stabilizer version.
I think we need to get rid of the probability stuff and use percentages.

To me it is totally unclear what the range of the values, and since it is unclear to me, it is unclear to most other developers. A percentage automatically includes the range 0..100. 

With probability you don't know the range 0..1? Or can you do e.g. writes vs reads is 4 to 3 ? But then the 'addOperationRemainingProbability' doesn't make any sense because you don't know what the total is, therefore you don't know what the remaining is.