A version of log4moz in the Thunderbird code base has preference-based controls. Shall we port this to toolkit/Log.jsm or do we need to bikeshed on the desired feature set first?

Needinfo requested from gps, who owns Log.jsm.

There are bugzilla comments somewhere (possibly bug 451283) about my opinions on this. Essentially: 1) Establish convention for defining logging settings via preferences. We can look at services.sync.log for inspiration. 2) Create a JavaScript component that reconciles preference values with Log4Moz loggers and handlers. 3) Create an XPCOM service that watches prefs branch(es) containing logging settings and have it update logging settings in real time.