Make JDT Ant's default compiler.  This makes JSPs work out of the box.

Review by: tobyr

git-svn-id: https://google-web-toolkit.googlecode.com/svn/releases/1.6@5109 8db76d5a-ed1c-0410-87a9-c151d255dfc7
diff --git a/dev/core/src/com/google/gwt/dev/shell/jetty/JettyLauncher.java b/dev/core/src/com/google/gwt/dev/shell/jetty/JettyLauncher.java
index c8d3010..1ab34db 100644
--- a/dev/core/src/com/google/gwt/dev/shell/jetty/JettyLauncher.java
+++ b/dev/core/src/com/google/gwt/dev/shell/jetty/JettyLauncher.java
@@ -431,6 +431,15 @@
     // Suppress spammy Jetty log initialization.
     System.setProperty("org.mortbay.log.class", JettyNullLogger.class.getName());
     Log.getLog();
+
+    /*
+     * Make JDT the default Ant compiler so that JSP compilation just works
+     * out-of-the-box. If we don't set this, it's very, very difficult to make
+     * JSP compilation work.
+     */
+    String antJavaC = System.getProperty("build.compiler",
+        "org.eclipse.jdt.core.JDTCompilerAdapter");
+    System.setProperty("build.compiler", antJavaC);
   }
 
   public ServletContainer start(TreeLogger logger, int port, File appRootDir)