Manage application state: foreground, background, terminated

Manage application state: foreground, background, terminated

Foreground / Background
  An application's lock is managed more strictly from the point when the
  application requires it. Now determine the memeber variable 'background'
  of PmLockNode based on the application's fg/bg state when adding lock
  as a new PmLockNode.

Terminated
  When an application is terminated without releasing lock, deviced unlocks
  it right away. At the same time, deviced decides whether to change state
  or not. At before, for this situation, it was responsible
  for pmlock_check() to release lingering lock of terminated application.

Change-Id: I70e66b69a5f3cdbfa54a2deb2e53ddf15d5456e1
Signed-off-by: Youngjae Cho <y0.cho@samsung.com>
Signed-off-by: lokilee73 <changjoo.lee@samsung.com>