* bin/common_aoutput.cc, bin/common_aoutput.hh, bin/common_setup.cc:
Implement it.
* NEWS, bin/man/spot-x.x: Document it.
* tests/core/readsave.test: Test it.
This is so that we can have -d as an alias for --dot everywhere.
* bin/randaut.cc: Rename -d as -e.
* NEWS: Mention the change.
* doc/org/autfilt.org, doc/org/oaut.org, doc/org/randaut.org,
tests/core/parseaut.test, tests/core/readsave.test: Adjust.