I merged in some of the background mail checking stuff. The new experimental
pop account type won't work until I check in an updated pop3 kioslave 
(which won't be for a few more days at least). But everything should still
compile and run fine(ish) anyway.

Hopefully everything is still fine, sorry if I messed things.

I'll write a more detailed report about how everything is meant to work once 
I've checked in the new pop3 kioslave. 

BFN,
Don.