allow explicit specification of ANT_HOME

git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@267668 13f79535-47bb-0310-9956-ffa450edef68

build.sh

@@ -1,6 +1,11 @@
 #!/bin/sh
 
-ADDL_CLASSPATH=./lib/ant.jar
+if [ "$ANT_HOME" == "" ] ; then
+  ANT_HOME=`pwd`
+fi
+export ANT_HOME
+
+ADDL_CLASSPATH=$ANT_HOME/lib/ant.jar
 
 if [ "$CLASSPATH" != "" ] ; then
   CLASSPATH=$CLASSPATH:$ADDL_CLASSPATH