Settings: don't remove navigation bar prefs when toggling

For devices which support the KeyDisabler class, toggling the nav bar
removes the navigation bar category, but does not add it back. If a
device can have the nav bar toggled, don't remove the category, but just
disable/enable it.

Change-Id: Ie527e3eb357e4a46097257d90c07c78e61f043a9
Signed-off-by: Roman Birg <roman@cyngn.com>
Settings: Only show clear button when search field has text.

Change-Id: I69bf6a31a933459be2c652434aec412105395dcc
Merge branch 'cm-11.0' into kk_mkt

Conflicts:
	src/com/android/settings/cyanogenmod/ButtonSettings.java

Change-Id: I2295d8bf0a148d4a1b3683fbe16ede2d7de9fbc2