API change from 2.3.* to 2.4.*

[Rice Yeh]

Hi,
  I try to upgrade apache cxf use from 2.3.* to 2.4.2 in my project but find
that there are some basic classes missed. The are
org.apache.cxf.interceptor.Fault, org.apache.cxf.message.Message,
org.apache.cxf.phase.Phase. These classes are quite basic for cxf. So there
must be some vital change in the 2.4. Where can I get more information on
this?
Rice