Upgraded HttpClient version to 4.4-alpha2-SNAPSHOT

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk@1606643 13f79535-47bb-0310-9956-ffa450edef68
Added new functionality to the pooling conn manager introduced by HTTPCORE-374
Contributed by Dmitry Potapov <potapov.d at gmail.com>

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk@1606665 13f79535-47bb-0310-9956-ffa450edef68
HTTPCLIENT-1524: RFC 2617 auth schemes (basic and digest) cannot handle auth parameters with mixed or upper case

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk@1606699 13f79535-47bb-0310-9956-ffa450edef68
HTTPCLIENT-1517: strip port and optionaly use canonical hostname when creating kerberos / gssapi context
Contributed by Sebastian Brabänder <apache-devel at brabaender-it.de>

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk@1610401 13f79535-47bb-0310-9956-ffa450edef68
HTTPCLIENT-1526: No User-Agent set in tunneled proxy connection

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk@1610598 13f79535-47bb-0310-9956-ffa450edef68
HTTPCLIENT-1527: fixed HttpCore OSGi imports

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk@1610616 13f79535-47bb-0310-9956-ffa450edef68