Merge pull request #2 from myarichuk/master

AbstractRaftStateBehavior::CommitEntries() should use lastIndex for commits
Merge pull request #3 from myarichuk/master

new node should start immediately topology changes
RaftEngine::CommitTopologyChange() should consider a node being taken out of repository _only_ if its name was present on previous topology and on requested it is not present.
This prevents considering the node removed from topology when it accepts new topology id (TopologyChangeCommand is run without previous topology and with empty Requested topology)