Relaxed OSGi dependency import version ranges. See HTTPASYNC-65

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk@1558380 13f79535-47bb-0310-9956-ffa450edef68
We have a concurrency bug in HttpCore 4.3.1 which will be addressed after HttpClient 4.3.2 is released.

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk@1558386 13f79535-47bb-0310-9956-ffa450edef68