put slave log files into specific directories.

changelog.html

@@ -55,6 +55,8 @@ Upcoming changes</a>
 <!-- Record your changes in the trunk here. -->
 <div id="trunk" style="display:none"><!--=TRUNK-BEGIN=-->
 <ul class=image>
+  <li class=rfe>
+    Slave logs are put into sub-directories to avoid cluttering $JENKINS_HOME
   <li class=rfe>
     Added "manage old data" permanently to the "manage Jenkins" page.
   <li class=rfe>

core/src/main/java/hudson/model/Computer.java

@@ -193,7 +193,9 @@ public /*transient*/ abstract class Computer extends Actionable implements Acces
      * This is where the log from the remote agent goes.
      */
     protected File getLogFile() {
-        return new File(Jenkins.getInstance().getRootDir(),"slave-"+nodeName+".log");
+        File dir = new File(Jenkins.getInstance().getRootDir(),"logs/slaves/"+nodeName);
+        dir.mkdirs();
+        return new File(dir,"slave.log");
     }
 
     /**