Add gesture based lockscreen security. [2/2]

PS2:
Tidy things up a bit.

Change-Id: I83e3ab643e19b2a2d9c8416f4925bbab05bbc896

Conflicts:
	res/values/strings.xml
	src/com/android/settings/SecuritySettings.java

Conflicts:
	src/com/android/settings/ChooseLockGeneric.java
fix