Print command errors to console.stderr instead of to the bare stderr.

Test Plan: buck build buck
diff --git a/src/com/facebook/buck/cli/AbstractCommandRunner.java b/src/com/facebook/buck/cli/AbstractCommandRunner.java
index 875979c..4e75311 100644
--- a/src/com/facebook/buck/cli/AbstractCommandRunner.java
+++ b/src/com/facebook/buck/cli/AbstractCommandRunner.java
@@ -84,11 +84,10 @@
 
     boolean hasValidOptions = false;
     try {
-
       parser.parseArgument(args);
       hasValidOptions = true;
     } catch (CmdLineException e) {
-      System.err.println(e.getMessage());
+      console.getStdErr().println(e.getMessage());
     }
 
     if (hasValidOptions && !options.showHelp()) {