obshashrangecache: precisely track affected revs when adding new markers This will be useful when we start doing finer grained invalidation (instead of dropping all data).

debugobshistory: handle multiple cycles We previously handled up to one cycle only. This is now fixed.

test: clean the debugobshistory cycle test Use 'desc(...)' instead of revision numbers. Also blank lines between commands in the same test

obsdiscovery: add more debug output we add a summary debug output to help gathering data.

discovery: log information about obshashrange We augment the blackbox output to help with data gathering.

obshistory: add a graph option on the debugobshistory command Add a graph option (--graph) to the debugobshistory. The output is like the 'hg log -G' output. The option is activated by default but can be deactivated with '--no-graph' option. There are various issue with the current implementation (multiple cycles handling, N² complexity) but this can be fixed later.

obshistory: import 'node' as 'nodemod' This simplify the next changeset.

label: add a label for the node in the "wc now at" message MOAR COLOR FOR THE COLOR GOAD!

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