topics: use a dict for successors of changesets produced by topic change
This patch adds a dictionary to store the successors of changesets which got
obsoleted when we change it's topic. This is an improvement in the fix for
issue5441.
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