Security Settings: cleanup layout
Settings : Scroll to preference on search and highlight

Change-Id: I93c4106d022b416205cc33cf5dbdf5d7635a002a
Highlight search string match.

Change-Id: I72c0380512028674c91f287325f221a686a4821d
Improve search performance.

The normalization regex is slow (5-10ms per entry on mako), so better
pre-cache it. Also cache the icons, as the number of icons is vastly
smaller than the number of potential search results, so they'll be
reused very often.

The regex change alone brings the duration of a single filter run down
to ~20ms from ~1200ms on mako.

Change-Id: Ia0fa9c554d0d585a52c8a2b87eecbf045388c961
Settings: Disable search item in some fragments.

Change-Id: I17ed6945f34f2fe7bb18674124f8a8989145b8c1

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