Use a dual pane layout instead of the navigation drawer for sw600dp screens or larger.

PS2: mActionBar should be assigned regardless of whether mDrawerLayout is null.

PS3: Use dual-pane layout when in landscape orientaiton.

Change-Id: If2c96cda691bab50ebd5d869f910a9351973367b
PreferenceFragment : Set title if specified

Set the title of the preference activity if specified by the
preference screen.

Example of where it is broken :

Settings -> Accessibility
Title says "Accessibility", but preferencescreen's android:title attribute
specified "Accessibility settings"

Change-Id: Icc89cf6bc37e3f6fc98c6bc05a0ef47185daa52c
Treat default value that wasn't found as empty value.

Fixes http://code.google.com/p/android/issues/detail?id=33220

Change-Id: If22e8b245f688d922c168aa54c8acf743c0644d7