Two hikers who were stranded on the Stairway to Heaven Trail in Kaneohe were both rescued by firefighters Monday morning.   The fire helicopter rescued a woman just before 7:30 a.m. and then went back to get the man.  Both appeared uninjured.  They called for help at 2 a.m. and were told to stay where they were until daylight, when fire rescuers could reach them.  The Stairway to Heaven Trail has been closed for years because of safety concerns.  The two hikers could be slapped with a fine for trespassing