Steps to ensure legacy client compatibility through ProtocolMetaData propagation - In progress, but initial testing seems OK.

Any Externalizable must respect order of readExternal and writeExternal and can now check the ProtocolMetaData for versioning on future changes.

Request and response handling are now separate methods, which ensures a more logical processing.

git-svn-id: https://svn.apache.org/repos/asf/tomee/tomee/trunk@1511348 13f79535-47bb-0310-9956-ffa450edef68