Reviewed-by: acorn, mchung, phh

Reviewed-by: mchung, dholmes

Summary: Add a JMX notification to GarbageCollectorMXBeans
Reviewed-by: acorn, mchung

Summary: Add getProcessCpuLoad() and getSystemCpuLoad() to the OperatingSystemMXBean
Reviewed-by: acorn, dholmes, mchung

Summary: Subclass com.sun.management.ThreadMXBean from java.lang.management.ThreadMXBean, add getAllocatedBytes() and friends to c.s.m.ThreadMXBean and have sun.management.ThreadImpl implement c.s.m.ThreadMXBean rather than j.l.m.ThreadMXBean.
Reviewed-by: mchung, alanb, dholmes, emcmanus

Reviewed-by: darcy, weijun