[imp] large session entries in horde_sessionhandler

[liam hoekenga]

> What session *variable* contains these messages? This might help
> trapping down where it gets into the session data, if you are sure that
> message caching is turned off on your production server.

Is there an easy way to explode the session into it's component arrays?  The
blob seems to be comprised of a bunch of arrays and preferences, but it's not
contained in one big array, so we've found it hard to parse.

Liam