Reconfigure build.xml so -Xmacros isn't lost.

For future reference, -Dscalac.args is how unknown things
pass arbitrary parameters to scalac, so you don't want to put
anything there you don't expect to lose.

Author: paulp

build.xml

@@ -170,7 +170,7 @@ PROPERTIES
   <property file="${basedir}/build.number"/>
 
   <!-- Additional command line arguments for scalac. They are added to all build targets -->
-  <property name="scalac.args" value="-Xmacros"/>
+  <property name="scalac.args" value=""/>
   <property name="javac.args" value=""/>
 
   <!-- Sets location of pre-compiled libraries -->
@@ -314,12 +314,13 @@ INITIALISATION
   <target name="init.version.done" depends="init.version.release, init.version.snapshot"/>
 
   <target name="init" depends="init.jars, init.maven.jars, init.version.done">
+    <property name="scalac.args.always" value="-Xmacros" />
   <!-- scalac.args.optimise is selectively overridden in certain antcall tasks. -->
     <property name="scalac.args.optimise" value=""/>
   <!-- scalac.args.quickonly are added to quick.* targets but not others (particularly, locker.)
        This is to facilitate testing new command line options which do not yet exist in starr. -->
     <property name="scalac.args.quickonly" value=""/>
-    <property name="scalac.args.all" value="${scalac.args} ${scalac.args.optimise}"/>
+    <property name="scalac.args.all" value="${scalac.args.always} ${scalac.args} ${scalac.args.optimise}"/>
     <property name="scalac.args.quick" value="${scalac.args.all} ${scalac.args.quickonly}"/>
     <!-- Setting-up Ant contrib tasks -->
     <taskdef resource="net/sf/antcontrib/antlib.xml" classpath="${lib.dir}/ant/ant-contrib.jar"/>