Transition to new storage backend
After the file-based and the interim sqlite-based backlog storage, we will transition to a new storage backend. This will provide a common interface to different SQL backends (starting with Sqlite). In addition to providing the backlog, the storage backend also manages unique IDs for messages and buffers, and it stores and manages core users and their passwords.
Storage baseclass is already partly implemented. Sqlite backend has already mostly been implemented by EgS.