RadarGun 2.0 initial work
* new configuration
* removed local benchmark -> distributed benchmark can be executed in in-VM (master + 1 slave)
* communication refactored to Local/RemoteSlaveConnection and RemoteMasterConnection
* each group can use different plugin (product), config file and other properties
* Master/SlaveState now host information about configuration and cluster
TODO: Reporting is broken now (GenerateReportStage is not executed)