Fix https://issues.apache.org/bugzilla/show_bug.cgi?id=56223
Throw an IllegalStateException if a call is made to ServletContext.setInitParameter() after the ServletContext has been initialized

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1574943 13f79535-47bb-0310-9956-ffa450edef68
Fix broken test, uncovered by the fix for BZ 56223.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1575012 13f79535-47bb-0310-9956-ffa450edef68
Add experimental NIO2 connector
Switch the default connector back to NIO1
Remove forgotten debug.
- Fix socket <-> processor association when a read for the request line is pending.
- Go back to a more conventionnal accept thread in the end, it's simpler (although it did highlight the first issue somehow).
- Use a separate thread for timeouts since the acceptor is more conventional.
- Notice in some tests some issues with the blocking flush when ending a request, so add some code to make it wait for pending writes.
Improve on some non blocking IO issues, still working on output corruption in the test case
Non blocking error handling and cleanups.
- Fix upgrade init (and remove the hack).
- Fix input flip state in upgrade mode.