Fix ant warning about includeantruntime

According to https://stackoverflow.com/questions/5103384, ant 1.8
introduced a "misfeature" of providing the ant runtime by default in the
java classpath.  This causes some problems with reproducible builds,
which is why later versions have a warning not to do it.

The solution is to make the inclusion of ant.jar in the classpath
explicit.  That's been done now.

build/ACBuild-default.properties

@@ -5,6 +5,9 @@
 # ACBuild.properties.  That will allow you to change locations of
 # support files for local builds.
 #
+antJarPathWin=C:/Java/lib/ant1.10.1/ant.jar
+antJarPathMac=/opt/local/share/java/apache-ant/lib/ant.jar
+antJarPathUnix=/usr/share/java/ant.jar
 swtJarPathWin=C:/Program Files/Eclipse 2.1.x/plugins/org.eclipse.swt.win32_2.1.3/ws/win32/swt.jar
 swtJarPathMac=/Users/Shared/eclipse/plugins/org.eclipse.swt.carbon.macosx_3.3.3.v3349.jar
 swtJarPathUnix=/usr/share/java/swt.jar

build/build.xml

@@ -2,7 +2,12 @@
 	<description>
 		This script builds the distribution components.
 	</description>
-	
+
+	<!-- Fix ant warning (explained: https://stackoverflow.com/questions/5103384) -->
+	<presetdef name="javac">
+		<javac includeantruntime="false" />
+	</presetdef>
+
 	<property name="work" value="work"/>
 	<property name="classes" value="${work}/classes"/>
 	<property name="dist" value="${work}/dist"/>
@@ -15,6 +20,8 @@
 	<property name="builddir" value="${basedir}/build" />
 	<property file="${builddir}/ACBuild.properties"/>
 	<property file="${builddir}/ACBuild-default.properties"/>
+
+	<!-- If you want to add a platform, create a conditional property for it here -->
 	<condition property="isWin" value="true">
 		<os family="windows" />
 	</condition>
@@ -25,6 +32,7 @@
 		</and>
 	</condition>
 	<condition property="isUnix" value="true">
+		<!-- macOS also provides unix, so we must explicitly exclude it here -->
 		<and>
 			<os family="unix" />
 			<not>
@@ -32,6 +40,7 @@
 			</not>
 		</and>
 	</condition>
+
 	<condition property="signing-needed">
 		<available file="${keyconf}" property="keyconf-exists" />
 	</condition>
@@ -53,16 +62,19 @@
 	</target>
 
 	<target name="init-win" if="isWin">
+		<property name="antjar" value="${antJarPathWin}" />
 		<property name="swtjar" value="${swtJarPathWin}" />
 		<property name="juintjar" value="${junitPathWin}" />
 	</target>
 
 	<target name="init-mac" if="isMac">
+		<property name="antjar" value="${antJarPathMac}" />
 		<property name="swtjar" value="${swtJarPathMac}" />
 		<property name="juintjar" value="${junitPathMac}" />
 	</target>
 
 	<target name="init-unix" if="isUnix">
+		<property name="antjar" value="${antJarPathUnix}" />
 		<property name="swtjar" value="${swtJarPathUnix}" />
 		<property name="juintjar" value="${junitPathUnix}" />
 	</target>
@@ -107,7 +119,7 @@
 	</target>
 	
 	<target name="executableGuiJar" depends="init" description="Build GUI executable JAR">
-		<javac srcdir="${source}" destdir="${classes}" classpath="${swtjar}">
+		<javac srcdir="${source}" destdir="${classes}" classpath="${antjar}:${swtjar}">
 			<include name="**/*.java"/>
 			<exclude name="**/*Test.java"/>
 		</javac>
@@ -127,7 +139,7 @@
 	</target>
 	
 	<target name="executableCmdJar" depends="init" description="Build command-line only executable JAR">
-		<javac srcdir="${source}" destdir="${classes}" >
+		<javac srcdir="${source}" destdir="${classes}" classpath="${antjar}">
 			<include name="**/*.java"/>
 			<exclude name="**/*Test.java"/>
 			<compilerarg value="-XDignore.symbol.file"/>