Update version of httpclient to 4.2.5

git-svn-id: https://svn.apache.org/repos/asf/jena/trunk@1511778 13f79535-47bb-0310-9956-ffa450edef68
Clear up for JENA-498 
Per request creation of an HttpClient is still the default due to lock-up when recycled.

git-svn-id: https://svn.apache.org/repos/asf/jena/trunk@1511783 13f79535-47bb-0310-9956-ffa450edef68
Downgrade version of httpclient to 4.2.3 due to solrj using 4.2.3

git-svn-id: https://svn.apache.org/repos/asf/jena/trunk@1511787 13f79535-47bb-0310-9956-ffa450edef68
Merge remote-tracking branch: upstream/trunk