obshashrange: re-warm less revision after reset
rewarming every single revision get very expensive quickly. Instead we warm few
key revision and rely on the fact this will warm enough useful subrange.
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