Updated project web site for HttpClient 4.3-beta2 release

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk@1490992 13f79535-47bb-0310-9956-ffa450edef68
Updated HttpClient 4.3-beta2 release notes

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk@1490993 13f79535-47bb-0310-9956-ffa450edef68