I second the idea, since I was planningto make a very similar suggestion. I do not care whether via svn, or database, or both, just choose the best, or most practical implementation.
I'd also suggest to have a "tool" key. While it is always fine to recycle messages elsewhere, there is a risk to it. Messages can be changed. Because of that, there should be one master, or one place of authority having the final say, else we might run into "edit war" situations when altering shared messages. In other words: If it is not *my* tools key, and an amdeded message is not useable any more, *I* must go and seek or create another one.
Have fun at FOSDEM!
Greetings, Purodha