Settings new dashboard - part 2

Introduce the new Dashboard (a grid like presentation of
Settings top categories) per UX specification.

- the Dashboard is composed of "categories" and in each of them
you have "tiles"
- implement a new layout for showing top categories
(DashboardContainerView). This layout basically acts like a
grid
- depending on the device configuration make the grid with 1
column in portrait / 2 colums in landscape (phones) OR 2 columns
in portrait and 3 in landscape (tablets)
- take care of Accounts adding and removing (as it changes the
number of tiles to show)

Also remove all the old code related to Headers

Change-Id: Ie29944132c1b4c3f7b073d5a7d4453b8f5ec19a7

src/com/android/settings/SoundSettings.java

@@ -141,7 +141,10 @@ public class SoundSettings extends SettingsPreferenceFragment implements
 
         if (TelephonyManager.PHONE_TYPE_CDMA != activePhoneType) {
             // device is not CDMA, do not display CDMA emergency_tone
-            getPreferenceScreen().removePreference(findPreference(KEY_EMERGENCY_TONE));
+            Preference pref = findPreference(KEY_EMERGENCY_TONE);
+            if (pref != null) {
+                getPreferenceScreen().removePreference(pref);
+            }
         }
 
         if (!getResources().getBoolean(R.bool.has_silent_mode)) {
@@ -150,7 +153,10 @@ public class SoundSettings extends SettingsPreferenceFragment implements
 
         if (getResources().getBoolean(com.android.internal.R.bool.config_useFixedVolume)) {
             // device with fixed volume policy, do not display volumes submenu
-            getPreferenceScreen().removePreference(findPreference(KEY_RING_VOLUME));
+            Preference pref = findPreference(KEY_RING_VOLUME);
+            if (pref != null) {
+                getPreferenceScreen().removePreference(pref);
+            }
         }
 
         mVibrateWhenRinging = (CheckBoxPreference) findPreference(KEY_VIBRATE);