Updated build.xml for macosx 10.9

Author: cmaglie

build.xml

@@ -25,6 +25,14 @@ or visit www.oracle.com if you need additional information or have any
 questions.
 -->
 
+<!--
+On macosx the JAVA_HOME env variable may be set with the
+following command:
+
+    export JAVA_HOME=$(/usr/libexec/java_home)
+
+-->
+
 <project name="appbundler" default="package">
     <property environment="env"/>
     <property file="build.properties"/>
@@ -73,7 +81,7 @@ questions.
             <arg value="-arch"/>
             <arg value="x86_64"/>
             <arg value="-isysroot"/>
-            <arg value="/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.8.sdk"/>
+            <arg value="/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk"/>
             <arg value="-mmacosx-version-min=10.8"/>
             <arg value="appbundler/native/main.m"/>
         </exec>