Integrated Encryption

[joe42]

Nubisave should be able to optionally encrypt data instead of relying on Encfs file system, for better integration, and to use the existing multi-threading infrastructure. This would enable context analysis, compression, and deduplication despite of the encryption of the complete data stream, reduce the amount of seperate databases, and decrease external dependencies.
Encryption should be configured via the configuration file in a separate [Encryption] section.