test_index.c: added index clear example and use activated callback for entry.
test_index.c: added index clear example and use activated callback for entry.

FlorentRevest/Elementary,tasn/elementary,tasn/elementary,tasn/elementary,FlorentRevest/Elementary,rvandegrift/elementary,rvandegrift/elementary,tasn/elementary,FlorentRevest/Elementary,FlorentRevest/Elementary,tasn/elementary,rvandegrift/elementary,rvandegrift/elementary