Fix copyright notices in strings.xml files

jsettlers.main.android/src/main/res/values-de/strings.xml

@@ -1,4 +1,19 @@
 <?xml version="1.0" encoding="utf-8"?>
+<!--
+  ~ Copyright (c) 2015 - 2017
+  ~
+  ~ Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"),
+  ~ to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,
+  ~ and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+  ~
+  ~ The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+  ~
+  ~ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+  ~ FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+  ~ LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+  ~ DEALINGS IN THE SOFTWARE.
+  -->
+
 <resources>
     <string name="app_name">JSettlers</string>
     <string name="please_wait">Bitte warten</string>

jsettlers.main.android/src/main/res/values/strings.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="utf-8"?>
 <!--
-  ~ Copyright (c) 2017
+  ~ Copyright (c) 2015 - 2017
   ~
   ~ Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"),
   ~ to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense,