tests: add tests of content+parent change creating phase-divergence
This patch adds tests which shows handling of phase divergence cases by `hg
evolve` command which involved content+parent change. The conflicts case is not
handled and will be fixed in upcoming patches.
mkdir -p html
cp index.html html/
cp *.css html/
cp *.js html/
cp -R img html/
cp -R graphviz-images/ html/
netlify deploy