[PATCH 1 of 8] largefiles: replace "_isXXXXing" attributes with "_lfautocommit"

[Sean Farley]

Mads Kiilerich writes:

> I wonder if we should try a different approach. As you point out, it is 
> almost impossible to do the right thing in the internal commit functions 
> - they don't have enough context. One alternative could be to hook in at 
> the very low level, updating the standin files whenever they are read 
> and propagate their change whenever they are written. Another approach 
> would be to do all synchronization before/after calling in to core 
> Mercurial and let the core pretty much treat standin files like any 
> other file. I have played around with that approach and posted a proof 
> of concept.

Just a shot in the dark here, but what about using a custom context
object (that will soon grow a commit method)?