Several improvements when retrieving summary information

[Philip Van Hoof <spam pvanhoof be>]

I also found what was probably the locking problem that I was seeing.

Upon cancellation there was, indeed, unhandled code that should early-
stop rather than continue trying to do things (which is what summary
retrieval was vigorously trying to do).

On performance there are also some improvements (speed improvements)
committed.


Sorry, no Lemonade features yet :)

-- 
Philip Van Hoof, software developer
home: me at pvanhoof dot be 
gnome: pvanhoof at gnome dot org 
http://www.pvanhoof.be/blog