Add experimental NIO2 connector. Based on code developed by Nabil Benothman.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1575905 13f79535-47bb-0310-9956-ffa450edef68
Followup to r1575885
Do not hold writeLock when calling onError().

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1575910 13f79535-47bb-0310-9956-ffa450edef68
Followup to r1575905:
svn:eol-style=native for new files

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1575919 13f79535-47bb-0310-9956-ffa450edef68