IGMPv3: fix the initial state of multicast groups in routers
IGMPv3: fix INCLUDE (A) --TO_EX (B)--> EXCLUDE (A*B,B-A) state transition

The source list of the sent Group-and-Source-Specific Query was wrong.
IGMPv3: add comment
IPv4InterfaceData: added setMulticastListeners() method
IGMPv3: updating the interface state when a report was processed
IGMPv3: added a module test for checking the interface state after reports are processed
IGMPv3: renamed SourceToGroupDataMap
IGMPv3: eliminated timer context classes by restructuring router/host data
IGMPv3: use startTimer method where possible
IGMPv3: fix control flow in processQuery() method
IGMPv3: cosmetics
IGMPv3: host/router group statistics are updated when the group data created/deleted
IGMPv3: refactoring
IGMPv3: eliminated last timer context class