Add gesture based lockscreen security. [2/2]

PS2:
Tidy things up a bit.

Change-Id: I83e3ab643e19b2a2d9c8416f4925bbab05bbc896

Conflicts:
	src/com/android/settings/SecuritySettings.java

Conflicts:
	res/values/pac_strings.xml

Conflicts:

	src/com/android/settings/SecuritySettings.java
Add isValidFragment to various lock settings

Change-Id: Ia79fd5e3c9f829b919c5f8f9abf6ecc606434f18
Allow using a gesture lock when adding users.

Change-Id: I20e2d09b98fa174ad47d96f206332794001c22b9
Small Fix