The old format was fine as long as I only moved between C++ and Java.
Now I am also setting in Python where the doc strings are written after the "declaration". This made it harder to read.
so that blockattack.data builds in a reproducible way
in spite of indeterministic filesystem readdir order
See https://reproducible-builds.org/ for why this is good.
Also call gzip -n to omit build time from .gz header.