Refactor suspend sequence

Refactor suspend sequence

1) Bring forward suspend time when before-quit.
 ** When OnTerminate is coming first earlier than OnPause,
  'quit' makes this.webApplication as undefined, then
  wrt.on('suspend'...) will be skipped. This means that
  With normal termination sequence, suspending might be not
  handled.

2) Even though background runnable app, when app is in quitting,
 enable suspend sequence for right termination sequence.

Change-Id: Ie40f650ea317d6f198f9c1c1aa07c9bc6867b693
Signed-off-by: DongHyun Song <dh81.song@samsung.com>