Support screen rotation for "Delete All Tracks".

Replace DeleteAllTracks and DeleteTrack with
confirmation dialogs.

Currently, for DeleteTrack, the listener code in
repeated twice in MapActivity and TrackList. But in the
ICS design, DeleteTrack will only be available in
one place.

MyTracks/AndroidManifest.xml

@@ -181,16 +181,6 @@ limitations under the License.
       </intent-filter>
     </activity>
 
-    <activity android:name="com.google.android.apps.mytracks.DeleteTrack"
-              android:theme="@android:style/Theme.Translucent.NoTitleBar"
-              android:noHistory="true">
-      <intent-filter>
-        <action android:name="android.intent.action.DELETE" />
-        <category android:name="android.intent.category.DEFAULT" />
-        <data android:mimeType="vnd.android.cursor.item/vnd.google.track" />
-      </intent-filter>
-    </activity>
-
     <activity android:name="com.google.android.apps.mytracks.WaypointDetails"
               android:label="@string/marker_detail_title">
       <intent-filter>