Microoptimization: DefaultPivotModel: move filter.isEmpty() branch out of the loop, and cache the constant dataSource.getRowCount().
Remove unneeded array allocation. Just pass a Collection.
Reduced direct access to getAggregator() of the pivot field.
First basic support for FieldCalculations, e.g. % fieldA of fieldB, or
fieldA + fieldB
The FieldCalculation got a title, so that you can have a nice name in the exports.
Merge remote-tracking branch 'upstream/master' into fieldcalculations

Conflicts:
	wicket-pivot/src/main/java/ro/fortsoft/wicket/pivot/PivotUtils.java
Merge pull request #11 from rototor/fieldcalculations

FieldCalculations: Calculate % A of B