Changeset 4267 for branches/3.3-HiveMigration/sources/HeuristicLab.Hive/HeuristicLab.Hive.Server.LINQDataAccess/3.3/SlaveConfigDao.cs

renamed all database entities from "Client" to "Slave" (#1157)
made slave-heartbeats synchronous, also they send HBs when timetable disallows them to calculate. they will appear on the server as Idle bis IsAllowedToCalculate will be false (#1159)