adl/hoaf — pull request #28 by adl (2014-06-10 08:42:01+00:00)
Title: stutter-invariant property

Joachim suggests we support a `stutter-invariant` property.

Some algorithms ([like `ltl2dstar`'s Safra's implementation](http://link.springer.com/chapter/10.1007%2F978-3-540-76336-9_7)) can be improved on such automata.

Makes sense to me.