Ensure that test goals of one ECP_Atom are exclusive
Ensure that test goals of one ECP_Atom are exclusive

- Previously, path coverage could yield more than one test goal state on one
  path through the automaton
- Makes assertion in constraint_strengthening.cpp:82 invalid and causes problems
  with upcoming move to groupwise constraint strengthening

git-svn-id: 2bf0a26aea6c62cd51edc7db6f8f24500077f83b@311 740c81f5-4728-4b1f-bc77-cf82a461b733

tautschnig/fshell,tautschnig/fshell,tautschnig/fshell,tautschnig/fshell