evolve: add -i flag to amend command The -i flag was missing because it is not a global flag of the commit command. We can't make it a global flag yet as it is used in many places where it would not be appropriate so we just add it for this occurrence. Also, we only want to add it when commit supports it (otherwise it wouldn't work with older versions of mercurial)

test-drop.t
test-simple4server.t
tests/test-simple4server-bundle2.t