Code review comment for lp:~weyrick/bzr/54624-warn-on-large-files

All the goals have been met in the current patch, except 5 and 2. 5 I'm not doing for now. 2 is a larger problem - some informal tests importing large trees show about 23% slowdown with the extra stat. Unfortunately I don't see a simple path towards sharing stat calls - they seem to be spread throughout the code now with no central way to cache. I'm looking into this further now.