Change instance initializer in About.java to static.  Most of the work, though, was on the Ant files such that once the filtered copies have already been generated, they will re-generate IFF the gwt OR svn versions have changed (i.e. after an svn up).

Review by: scottb

git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@3646 8db76d5a-ed1c-0410-87a9-c151d255dfc7
diff --git a/dev/common.ant.xml b/dev/common.ant.xml
index 58266be..4353204 100755
--- a/dev/common.ant.xml
+++ b/dev/common.ant.xml
@@ -19,8 +19,11 @@
   <target name="build" depends="compile" description="Build and package this project">
     <mkdir dir="${gwt.build.lib}" />
     <gwt.jar>
-      <fileset dir="src" excludes="**/package.html" />
-      <fileset dir="${gwt.core.root}/src" excludes="**/package.html" />
+      <fileset dir="src" excludes="**/package.html"/>
+      <fileset dir="${gwt.core.root}/src">
+        <exclude name="**/package.html"/>
+        <exclude name="com/google/gwt/dev/About.properties"/>
+      </fileset>
       <fileset dir="${gwt.core.root}/super" excludes="**/package.html" />
       <fileset dir="${javac.out}" />
       <fileset dir="${gwt.core.build}/bin" />