Better cross-platform installation (e.g. respecting DESTDIR). The
Makefile now requires gmake.
Various suggestions from shellcheck.
Clarify why -e is forbidden unless -o is also specified.
Document that -e sends combined stderr/stdout output to stdout.
Error if -e is specified without -o, since the previous behaviour of -e
without -o had no use (and mildly surprising semantics).
Use the OS’s basename program rather than a hand-rolled alternative.
First release.