label: rename 'evolve.short_node' to 'evolve.node' A wider labelk will helps compatibility.

obshistory: refactor debugobshistory Rename the function and extract the heavy work of the command in a separate module named obshistory.py

test: adapt to change in cache warming in core Core Mercurial has a more rational cache warming strategy now. 24f55686a63d stopped warming of the cache after every changegroup application (in favor of end of transaction warming). This reflect in the blackbox test output.