Found problems in the replication ECL code.
Also made the code more explicit.


DraftCNBDHandler.java, ChangelogDB.java:
Renamed firstkey and lastkey to firstDraftCN and lastDraftCN + renamed getters too.
In clear() added very a important comment about unreliable method call + renamed currentkey local variable to currentDraftCN + used final keyword.

ECLServerHandler.java:
Renamed all the *Key local variables to *DraftCN where possible.

ReplicationServer.java:
Renamed field replicationServers to replicationServerUrls.
Changed excludedBaseDNs from Collection to Set.
Did some renaming here and there.
Extracted method contains().
In getECLDraftCNLimits(), used primitive variables. There was some code that worked by chance more than by design: see in the old code "if (newestDate == 0L)"

DraftCNDbHandlerTest.java:
Renamed firstkey to firstDraftCN.