Make system layout fill the window properly on expanded desktop mode

This commit fixes e.g. the gap on the bottom of the lock screen
or the gap on the right side of status bar on landscape mode.

Patch set 2  : Remove whitespace issues
Patch set 3  : Code cleanup
Patch set 4  : Damn whitespace errors

Change-Id: Ic8a6b748f94d7dcc883201579d199898713c90fd
Fix up expanded desktop behaviour.

The expanded desktop mode had a number of issues:
- It didn't handle multi-user scenarios correctly
- In the keyguard, the status bar was shown while the navigation bar was
  hidden, which was inconsistent to the !keyguard case
- Live wallpaper sizing was incorrect when expanded desktop mode was
  enabled due wallpaper windows not being recalculated correctly after
  enabling expanded desktop

This patch should fix all of those items.

Change-Id: I976ffae3a56d411b00026f86b16efa9743a23293

Conflicts:

	policy/src/com/android/internal/policy/impl/PhoneWindowManager.java
	services/java/com/android/server/wm/WindowState.java