Removes "infinite staleness" in user build from non-compilable package-info.java classes.

Review by: knorton


git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@2343 8db76d5a-ed1c-0410-87a9-c151d255dfc7
diff --git a/common.ant.xml b/common.ant.xml
index eae0885..e70f9bb 100755
--- a/common.ant.xml
+++ b/common.ant.xml
@@ -114,7 +114,9 @@
 	</presetdef>
 
 	<presetdef name="gwt.javac">
-		<javac srcdir="src" destdir="${javac.out}" debug="${javac.debug}" debuglevel="${javac.debuglevel}" source="${javac.source}" target="${javac.target}" nowarn="${javac.nowarn}" encoding="${javac.encoding}" />
+		<javac srcdir="src" destdir="${javac.out}" debug="${javac.debug}" debuglevel="${javac.debuglevel}" source="${javac.source}" target="${javac.target}" nowarn="${javac.nowarn}" encoding="${javac.encoding}">
+			<exclude name="**/package-info.java"/>
+		</javac>
 	</presetdef>
 
 	<presetdef name="gwt.jar">