upgrade to "android 1.6, but still works on 1.5"

AndroidManifest.xml

@@ -2,7 +2,13 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     android:versionCode="1991"
     android:versionName="1.991" package="com.fsck.k9">
-    <uses-sdk android:minSdkVersion="3"/>
+	<uses-sdk
+	   android:minSdkVersion="3"
+	   android:targetSdkVersion="4"
+	   />
+   <supports-screens
+
+	/>
     <uses-permission android:name="android.permission.RECEIVE_BOOT_COMPLETED"/>
     <uses-permission android:name="android.permission.READ_CONTACTS"/>
     <uses-permission android:name="android.permission.READ_OWNER_DATA"/>

build.properties

@@ -1,2 +1,2 @@
 application-package=com.fsck.k9
-
+target=android-4

build.xml

@@ -182,7 +182,7 @@
 
     <!-- Compile this project's .java files into .class files. -->
     <target name="compile" depends="resource-src, aidl">
-        <javac encoding="ascii" target="1.5" debug="true" extdirs=""
+        <javac encoding="ascii" target="1.6" debug="true" extdirs=""
                 destdir="${out-classes}"
                 bootclasspathref="android.target.classpath">
             <src path="${source-folder}" />
@@ -190,7 +190,7 @@
             <classpath>
                 <fileset dir="${external-libs-folder}" includes="*.jar"/>
                 <fileset dir="${compile-only-libs-folder}" includes="*.jar"/>
-                <fileset dir="${sdk-location}/platforms/android-1.5/" includes="**/*.jar"/>
+                <fileset dir="${sdk-location}/platforms/android-1.6/" includes="**/*.jar"/>
                 <pathelement path="${main-out-classes}"/>
             </classpath>
          </javac>