config: dotenv files are parsed, never sourced, so a value can hold a # or a
$(...) without breaking or executing. The make engine included .env with
make syntax, which neither allowed.
compose: one call per project instead of one per sub-stack.
Replaces the 500-character stack_path expression of
make/apps/def.docker.mk:159 and its leaked $(stackz) loop variable with
three readable functions, covered by 20 assertions.
Ported from make/utils.mk, make/def.mk, make/apps/def.docker.mk and
make/apps/def.mk, with the examples that sat as dead comments in
make/apps/def.mk turned into actual assertions.
Two deviations from the make macros are pinned and documented in DELTAS.md;
both only show up on code paths nothing uses.
Yann Autissier