Incorrect info in notifications with distributed build enabled

When the master creates email notifications, it picks up the hostname, OS, Java and Maven version info from itself rather than from the agent on which the build actually happened.

This section of the email notification needs to be fixed:

Building machine hostname: buildserver.example.com
Operating system : Linux(unknown)
Java Home version :
java version "1.6.0_13"
Java(TM) SE Runtime Environment (build 1.6.0_13-b03)
Java HotSpot(TM) Server VM (build 11.3-b02, mixed mode)

Builder version :
Apache Maven 2.2.x...
Java version: 1.6.0_13
Java home: /usr/java/jdk1.6.0_13/jre
Default locale: en_US, platform encoding: UTF-8
OS name: "linux" version: "2.6.18-8.el5pae" arch: "i386" Family: "unix"

(Note that the server is running under a JRE, but the build obviously couldn't be...)