e_test_event: supporting multiple event

e_test_event: supporting multiple event

existing e_test_event can support only single event that registered window.
this patch makes e_test_event can support multiple event of all of testcase's window.

From now on, you can use waitEvent without registerTCWin.
but, waitEvent needs etWin pointer to check event.

Change-Id: I3cc9d92db78bc5d52d4b11a9b56af45d493a58a2