Comment 1 for bug 440631

The discussion with John was about has_changes() being used in several places in mostly the same way but with
differences with no good justifications.

This became more apparent with the addition of the --strict option to push, send, dpush, etc.
Some commands were doing some checks but roughly all the call sites wanted a way
to represent that the working tree has no changes worth committing.
All of them also always compare to their basis tree.

So during a review, John asked for a single method without parameter for all these use cases.