Eliminated looping in content received event (input ready loop is now performed by the I/O reactor)

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpasyncclient/trunk@1628148 13f79535-47bb-0310-9956-ffa450edef68
Upgraded HttpClient to version 4.4-beta1

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpasyncclient/trunk@1628149 13f79535-47bb-0310-9956-ffa450edef68