title: updating relative path of jar while working on different OS
body: <p>I would like to replace path of an existing jar based on OS .
  Right now i am maintaning a text file called "build.start.properties" with all libraries some ting like this<br>
  /gwt/X/2.1.0/gwt-servlet.jar<br>
  /gwt/X/2.1.0/gwt-user.jar
  /gwt/X/2.1.0/gwt-dev.jar<br>
  /gwt/X/2.1.0/gwt-soyc-vis.jar 
  /log4j/X/1.2.15/log4j-1.2.15.jar
  /GWT_LOG/X/3.0.3/gwt-log-3.0.3.jar
  /GWT_MATH/X/2.1/gwt-math-2.1.jar
  /GWT_MATH/X/2.1/gwt-math-server-2.1.jar 
  /GWT_Commons_Logging/X/0.3/GWT-commons-logging/gwt-commons-logging-0.3.jar<br>
  /GWT_Commons_Logging/X/0.3/GWT-commons-logging/gwt-commons-logging-service-0.3.jar  </p>
  
  <p>And loading them to classptah using below target</p>
  
  <p></p>
  
  <pre><code>    &lt;loadfile property="jars.list.property" srcfile="mybuild/build.start.properties"&gt;
          &lt;filterchain&gt;
              &lt;expandproperties /&gt;
              &lt;striplinecomments&gt;
                  &lt;comment value="#" /&gt;
              &lt;/striplinecomments&gt;
              &lt;tokenfilter&gt;
                  &lt;ignoreblank /&gt;
              &lt;/tokenfilter&gt;
              &lt;prefixlines prefix="," /&gt;
              &lt;striplinebreaks /&gt;
          &lt;/filterchain&gt;
      &lt;/loadfile&gt;
      &lt;filelist id="build.libs" dir="" files="${jars.list.property}" /&gt;
  
      &lt;pathconvert targetos="unix" property="build_unix.libs" refid="build.libs"&gt;
  
          &lt;map from="C:" to="${unix.xenv}" /&gt;
          &lt;map from="" to="${unix.xenv}" /&gt;
      &lt;/pathconvert&gt;
      &lt;pathconvert targetos="windows" property="build_windows.libs" refid="build.libs"&gt;
          &lt;map from="C:" to="${windows.xenv}" /&gt;
          &lt;map from="" to="${windows.xenv}" /&gt;
      &lt;/pathconvert&gt;
      &lt;path id="build.classpath.id"&gt;
          &lt;pathelement path="${build_windows.libs}" /&gt;
          &lt;pathelement path="${build_unix.libs}" /&gt;
      &lt;/path&gt;
      &lt;echo message="Build Libraries classpath: ${toString:build.classpath.id}" /&gt;
  &lt;/target&gt;
  </code></pre>
  
  <p>from the above target build.classpath.id looks like 
  /gwt/X/2.1.0/gwt-servlet.jar:/gwt/X/2.1.0/gwt-user.jar:/gwt/X/2.1.0/gwt-dev.jar:/gwt/X/2.1.0/gwt-soyc-vis.jar:/log4j/X/1.2.15/log4j-1.2.15.jar:/GWT_LOG/X/3.0.3/gwt-log-3.0.3.jar:GWT_MATH/X/2.1/gwt-math-2.1.jar:/GWT_MATH/X/2.1/gwt-math-server-2.1.jar:/GWT_Commons_Logging/X/0.3/GWT-commons-logging/gwt-commons-logging-0.3.jar:/GWT_Commons_Logging/X/0.3/GWT-commons-logging/gwt-commons-logging-service-0.3.jar</p>
  
  <p>When i work on unix I have to pic only jar names from file "build.start.properties" and update path like this    </p>
  
  <p>/WebContent/WEB_INF/lib/gwt-servlet.jar:/WebContent/WEB_INF/lib/gwt-user.jar:/WebContent/WEB_INF/lib/gwt-dev.jar:/WebContent/WEB_INF/lib/gwt-soyc-vis.jar:/WebContent/WEB_INF/lib/log4j-1.2.15.jar:/WebContent/WEB_INF/lib/gwt-log-3.0.3.jar:/WebContent/WEB_INF/lib/gwt-math-2.1.jar:/WebContent/WEB_INF/lib/gwt-math-server-2.1.jar:/WebContent/WEB_INF/lib/gwt-commons-logging-0.3.jar:/WebContent/WEB_INF/lib/gwt-commons-logging-service-0.3.jar</p>