evolve: extend obsstore object to use prune parent information
Now that we have the information, we can use it to build a mapping to access all
marker that prune a children of a node. This is similar to what we do for
successors and precursors.
The performance impact is a few tens of second on my mercurial clone.
Experimenting is worth the trouble.
all: tutorials/tutorial.rst static/logo-evolve.ico
sphinx-build . ../html/
tutorials/tutorial.rst: tutorials/tutorial.t
python test2rst.py tutorials/
static/logo-evolve.ico: static/logo-evolve.svg
convert -resize 36x36 static/logo-evolve.svg static/logo-evolve.ico