rework refactor _aspiringchildren by introducing _possibledestination
This allows us to reuse some of the logic for evolve from _aspiringchildren
for the new implementation of evolve --all.
The logic is also better as some previously selected changesets may not actually
evolve on the target, and some changesets that does not would not.
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