[2/2] Left handed navbar during landscape mode

This patch allows for the navbar to be moved to the left side of the
screen during landscape mode. Left handed people are more used to this
option.

This patch must go with another patch that changes
packages/apps/Settings

Screenshot: http://i.imgur.com/jWqJcEV.png

Change-Id: Ic95e3fda1f55efd2ec908c8d7226e638ec0ab80a

Conflicts:
	core/java/android/provider/Settings.java
	policy/src/com/android/internal/policy/impl/PhoneWindowManager.java