Refactoring. Extract ByteBufferHolder into a separate class that can be used by HTTP and AJP.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1520444 13f79535-47bb-0310-9956-ffa450edef68
Increase size of output so a test client has a chance of triggering some buffering in the AJP processor

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1520446 13f79535-47bb-0310-9956-ffa450edef68
Add a simple non-blocking write test that currently fails. This won't impact the CI systems since the class is excluded from the unit tests.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1520447 13f79535-47bb-0310-9956-ffa450edef68