Settings: Don't match action bar parent for search on tablets.

Also adjust IME flags to
a) show the search icon as action key and
b) to not appear fullscreen in landscape

Change-Id: I9bc9851d39aa4d6dbed40df63dd4ea8df6f4c3f9
Settings: For the sake of search, don't split security settings.

    - There's also no good reason for having separate xml's for these.

Change-Id: I0216a2be10b801769eef7783f6c52a2b18b06aef
Settings: Disable search item in some fragments.

Change-Id: I17ed6945f34f2fe7bb18674124f8a8989145b8c1

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