fix, PEBKAC, it's _DARWIN_C_SOURCE, not _DARWIN_SOURCE

Signed-off-by: Sebastian Freundt <freundt@fresse.org>
Merge branch 'bld/dist'

* bld/dist:
  fix, PEBKAC, it's _DARWIN_C_SOURCE, not _DARWIN_SOURCE
fix, globally avoid echo -n in git-version-gen script

Signed-off-by: Sebastian Freundt <freundt@fresse.org>
minor, go with echo -n for echo_n if that's supported

Signed-off-by: Sebastian Freundt <freundt@fresse.org>
fix, refrain from using $(...) backquotes, instead use `...` form

Signed-off-by: Sebastian Freundt <freundt@fresse.org>
Merge branch 'bld/dist' into next

* bld/dist:
  fix, refrain from using $(...) backquotes, instead use `...` form
  minor, go with echo -n for echo_n if that's supported
  fix, globally avoid echo -n in git-version-gen script