obshashrange: re-warm less revision after reset rewarming every single revision get very expensive quickly. Instead we warm few key revision and rely on the fact this will warm enough useful subrange.

effectflag: simplify meta data change testing Let us just do one larger test. G: changed hgext3rd/evolve/obshistory.py

effectflag: add a small comment to suggest improvement The code run but we will likely need something easier to extend.