evolve: allow updating to the successor if the parent is obsolete
Although 'hg update' handles this as well, it will also update to
tipmost descendent of the successor, if any.
all: tutorial static/logo-evolve.ico
sphinx-build . ../html/
tutorial:
python test2rst.py tutorials/
static/logo-evolve.ico: static/logo-evolve.svg
convert -resize 36x36 static/logo-evolve.svg static/logo-evolve.ico