Allow the build to work on other JDK versions than 1.3 because 1.3 crashes when doing a full build. Sets the compiler source and target to 1.3.

git-svn-id: https://svn.apache.org/repos/asf/xalan/java/branches/xalan-j_2_7_1_maint@1581621 13f79535-47bb-0310-9956-ffa450edef68