Hello!

I have noticed that git-*-fetch now uses much more CPU than it was
before the modifications to fix recovery after interrupted fetch.
Here is a series of small patches which fix the problems which I have
found (some of the fixes give pretty impressive results, like a 14x
decrease of CPU time); as a positive side effect, fetch.c becomes
slightly smaller and hopefully simpler than before.

-- 
Sergey Vlasov