add maven.compile.source property. Needed to work under JDK 1.5.0

git-svn-id: https://svn.apache.org/repos/asf/maven/maven-1/plugins/trunk@114938 13f79535-47bb-0310-9956-ffa450edef68

java/plugin.jelly

@@ -48,6 +48,7 @@
           excludes="**/package.html"
           debug="${maven.compile.debug}"
           deprecation="${maven.compile.deprecation}"
+          source="${maven.compile.source}"
           target="${maven.compile.target}"
           optimize="${maven.compile.optimize}">
           <ant:src>