Publisher has method getServerPrefix.
Refactoring of getIdPrefix in Publisher.
ID prefix can be requested from server.
IdGenerator class added.
Server_test slightly modified for better readability.
Tests for Subscriber added; some refactoring. IDs assigned by client.
Web example works again, with newest backend.
Tests for Subscription.
Collection is final public field in MongoProvider.
Random part of ID prefix is generated only once per Publisher instance.
DataProvider API changed: argument "_id" is no longer required in add and change methods, since it can be extracted from argument "data".
Timer removed from Subscription. Added possibility to start/stop receiving data from server.
MongoProvider concurrency issues resolved using collection locks.