revset.bisect: add new 'range' set to the bisect keyword The 'range' set is made of all changesets that make the bisection range, that is - csets that are ancestors of bad csets and descendants of good csets or - csets that are ancestors of good csets and descendants of bad csets That is, roughly equivalent of: bisect(good)::bisect(bad) | bisect(bad)::bisect(good) Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>