3.0 asynchronous machinery available.
Introduces a new improved Continuation API that is an evolution of the
original Continuation API, while taking some good ideas from the 3.0 spec.
The intention is that this API will simplify the use of the 3.0
API, while making it available in jetty-7 (scalably) and in all other
2.5 containers with the ContinuationFilter.
git-svn-id: svn+ssh://dev.eclipse.org/svnroot/rt/org.eclipse.jetty/jetty/trunk@27 7e9141cc-0065-0410-87d8-b60c137991c4