Add VPN settings classes to Settings app.

PATCH SET 2:
+ Add import com.android.settings.R

PATCH SET 3:
+ Remove @Override interface methods to be compilable by Java 1.5.

PATCH SET 4:
+ Add import android.net.vpn.VpnManager

PATCH SET 5:
+ Add license headers.

PATCH SET 6:
+ Remove Constant.java and move the constants to VpnSettings.
+ Make AuthenticationActor implement DialogInterface's handlers.
+ Remove trailing spaces.

PATCH SET 7:
+ Remove default username.

res/xml/vpn_edit.xml

@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2008 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.
+-->
+
+<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"
+        xmlns:settings="http://schemas.android.com/apk/res/com.android.settings">
+
+    <EditTextPreference
+        android:title="@string/vpn_name"
+        android:dialogTitle="@string/vpn_name"
+        android:key="vpn_name"
+        android:summary="@string/vpn_name_summary"
+        android:singleLine="true"/>
+
+</PreferenceScreen>   

res/xml/vpn_settings.xml

@@ -0,0 +1,36 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2008 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.
+-->
+
+<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"
+        android:title="@string/vpn_settings_activity_title">
+
+    <PreferenceScreen android:key="add_new_vpn"
+        android:title="@string/vpn_add_new_vpn">
+        <!--intent
+            android:action="android.intent.action.MAIN"
+            android:targetPackage="com.android.settings.vpn"
+            android:targetClass="com.android.settings.vpn.VpnEditor" /-->
+    </PreferenceScreen>
+
+    <!--CheckBoxPreference android:key="installer_enabled"
+            android:defaultValue="false"
+            android:title="@string/installer_enabled"
+            android:summaryOn="@string/installer_enabled_summary_on"
+            android:summaryOff="@string/installer_enabled_summary_off" /-->
+
+    <PreferenceCategory android:key="vpn_list" android:title="@string/vpns">
+    </PreferenceCategory>
+</PreferenceScreen>   

res/xml/vpn_type.xml

@@ -0,0 +1,21 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- Copyright (C) 2008 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.
+-->
+
+<PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android"
+        xmlns:settings="http://schemas.android.com/apk/res/com.android.settings"
+        android:title="@string/vpn_type_title">
+
+</PreferenceScreen>   

res/xml/wireless_settings.xml

@@ -52,6 +52,16 @@
                         android:targetClass="com.android.settings.bluetooth.BluetoothSettings" />
                 </PreferenceScreen>
 
+                <PreferenceScreen
+                    android:title="@string/vpn_settings_title"
+                    android:summary="@string/vpn_settings_summary"
+                    android:dependency="toggle_airplane">
+                    <intent
+                        android:action="android.intent.action.MAIN"
+                        android:targetPackage="com.android.settings"
+                        android:targetClass="com.android.settings.vpn.VpnSettings" />
+                </PreferenceScreen>
+
                 <PreferenceScreen
                     android:title="@string/network_settings_title"
                     android:summary="@string/network_settings_summary"