Middleware: Session Tracking

[ajbrown]

Allow tracking of all requests from a single browser session by automatically adding a session field to log messages.

[ajbrown]

This can be implemented now simply by generating the session identifier, storing it in the session storage, and adding it as a field using LogglyLoggerProvider.setExtra( { session: sessionId' } ) during setup. However, the goal of this enhancement is to abstract this process out.

We'll need:

• fallbacks when the storage interface is not available (cookies).
• automatic generation of the session identifier.
• enable/disable toggle for the feature (should be off by default).

[ajbrown]

This is starting to seem like it's out of scope for this project. It might be more suitable for some sort of plugin system.

[ajbrown]

Re-opening this as part of the 1.0.0 rewrite, which will include middleware.