obsnote: warn if user try to store a note in obsmarker on an older hg Support to store a note in obsmarker is from hg>=4.4. We have added notes support to all the evolve commands but we do support versions which don't support storing note in obsmarker. Warn if user tries to store a note in older hg.

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