Extract TextSecure strings for i18n.

1) Change all instances which use concatenation to build strings
with variables in them to use string formatting instead.

2) Extract all string literals from layouts and menus into strings.xml

3) Extract all string literals from code into strings.xml

res/layout/contact_selection_group_item.xml

@@ -1,21 +1,4 @@
 <?xml version="1.0" encoding="utf-8"?>
-<!--
-/*
- * Copyright 2009, The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
--->
 
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="fill_parent"