Removed usage of _appliedProgramObjectSet as it's no longer used by OSG applications and was causing a threading crash.

git-svn-id: http://svn.openscenegraph.org/osg/OpenSceneGraph/branches/OpenSceneGraph-3.2@14379 16af8721-9629-0410-8352-f15c8da7e697

include/osg/State

@@ -1336,11 +1336,6 @@ class OSG_EXPORT State : public Referenced, public Observer
             if (_lastAppliedProgramObject!=program)
             {
                 _lastAppliedProgramObject = program;
-                if (program && _appliedProgramObjectSet.count(program)==0)
-                {
-                    _appliedProgramObjectSet.insert(program);
-                    program->addObserver(this);
-                }
             }
         }
         inline const Program::PerContextProgram* getLastAppliedProgramObject() const { return _lastAppliedProgramObject; }