Display options: allow configuration of wake on plug behavior (2/2)

The PowerManager now checks Settings.Global.WAKE_WHEN_PLUGGED_OR_UNPLUGGED
to determine wake-on-plug behavior.  The configuration option
config_unplugTurnsOnScreen is used as the default value of the setting.

PS 2: Fix formatting of if statement

Cherry-picked from: I062794828831a2b6faf4293579103d2251f1bdd0

Change-Id: I7eefff468a64c04e536c377cff3c740a7e568ade
Merge "Display options: allow configuration of wake on plug behavior (2/2)" into cm-10.2
Clean up lockscreen target configuration code (1/2)

Get rid of a lot of duplicated code.

Change-Id: I80fb0b0cd9b5f7d79a5760f8fa6ae338d9ca7205
Merge branch 'cm-10.2' into martincz