Add unix build conditionals

Previously AC built onm Windows or not Windows (assumed to be Mac).
It appears there was a means to build using gcj, but this is not
necessary, does not work anymore as configured, and isn't what we want
anyway.

Here's a first pass at improving that situation.  It's a bit ugly at
present because it requires a lot of markup to do something that should
be simple.  Still, I'd rather do this in steps.

build/ACBuild-default.properties

@@ -7,7 +7,9 @@
 #
 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
 junitPathWin=C:/Java/lib/junit3.8.1/junit.jar
 junitPathMac=/Users/Shared/eclipse/plugins/org.junit_3.8.2.v200706111738/junit.jar
+junitPathUnix=/usr/share/java/junit.jar
 keyconf=${user.home}/.secret
-alias=name
+alias=name

build/build.xml

@@ -15,16 +15,41 @@
 	<property name="builddir" value="${basedir}/build" />
 	<property file="${builddir}/ACBuild.properties"/>
 	<property file="${builddir}/ACBuild-default.properties"/>
-	<condition property="swtjar"
+	<condition property="isWin" value="true">
-		value="${swtJarPathWin}"
+		<os family="windows" />
-		else="${swtJarPathMac}">
+	</condition>
-		<os family="windows"/>
+	<condition property="isMac" value="true">
-	</condition>	
+		<and>
-	<condition property="junitjar"
+			<os family="mac" />
-		value="${junitPathWin}"
+			<os family="unix" />
-		else="${junitPathMac}">
+		</and>
-		<os family="windows"/>
+	</condition>
-	</condition>	
+	<condition property="isUnix" value="true">
+		<and>
+			<os family="unix" />
+			<not>
+				<os family="mac" />
+			</not>
+		</and>
+	</condition>
+	<condition property="swtjar" value="${swtJarPathWin}">
+		<isset property="isWin" />
+	</condition>
+	<condition property="swtjar" value="${swtJarPathMac}">
+		<isset property="isMac" />
+	</condition>
+	<condition property="swtjar" value="${swtJarPathUnix}">
+		<isset property="isUnix" />
+	</condition>
+	<condition property="juintjar" value="${junitPathWin}">
+		<isset property="isWin" />
+	</condition>
+	<condition property="juintjar" value="${junitPathMac}">
+		<isset property="isMac" />
+	</condition>
+	<condition property="juintjar" value="${junitPathUnix}">
+		<isset property="isUnix" />
+	</condition>
 	<condition property="signing-needed">
 		<available file="${keyconf}" property="keyconf-exists" />
 	</condition>
@@ -203,4 +228,4 @@
 	        <zipfileset dir="${javadoc}" prefix="javadoc"/>
 	    </zip>
 	</target>
-</project>
+</project>