Offline working

The network always has latency far greater than the linux disk cache. A git diff can literally
be computed and displayed in the blink of an eye. This shows even more with being able to
merge, look at the result, re-merge to do it better (if needed) etc. All operations become
'cheaper', and many have noticed, just like Linus himself claimed, that there is a huge
difference between having to wait 10 seconds for an operation or just having it done by the
moment you press enter.