Students at Madison’s Edgewood College say other students are getting in trouble on campus — and getting away with it.  About 100 students walked out of class Wednesday to attend a student-led listening session.  They were dressed in black to show solidarity.  Some said the university’s administration didn’t do enough to condemn an act of vandalism during Dream Week when a poster of Doctor Martin Luther King Junior was vandalized.  About 20 students spoke directly to members of the president’s cabinet attending the event.  An organizer says this was the first open forum held on the Madison campus in at least eight years.