Search is now handled by TrackListActivity and MarkerListActivity.

* data is loaded via cursor,
* removed custom ranking (handled in database),
* search text is wrapped with wildcards, and
* search view can be closed by back button.

Fixes #492.

src/main/res/xml/searchable.xml

@@ -2,6 +2,4 @@
 <searchable xmlns:android="http://schemas.android.com/apk/res/android"
     android:hint="@string/menu_search"
     android:includeInGlobalSearch="false"
-    android:label="@string/app_name"
-    android:queryAfterZeroResults="true"
-    android:searchSettingsDescription="@string/search_global_description" />
+    android:label="@string/app_name" />