Pass Logs to a Database

[threeal]

Use file based database (maybe sqlite?).

• Put database in ~/.bro/log.db (this one only store logs).
• Modify log functions (log.Printf, log.Fatalf, etc.) so it could pass logs to that database.

The logs will be stored for each session (start -> exit), so there are two tables:

• List of session.
• List of logs.

The logs at least should store the following data:

• Time.
• Session Id.
• Topic (could be empty for now).
• Content.

While session for now just store start time of the session.