* spot/gen/automata.hh: State the precondition. * spot/gen/automata.cc: Catch n==0. * tests/core/genaut.test: Test it.
* bin/genaut.cc: Use RANGE instead of N, and document it. Output the FORMAT documentation, and fix handling of %F and %L. * tests/core/genaut.test: New file. * tests/Makefile.am: Add it.