HTTPCLIENT-1432: Lazy decompressing of HttpEntity#getContent() to avoid EOFExceptionin case of an empty response with 'Content-Encoding: gzip' header.
Contributed by Yihua Huang <code4crafter at gmail.com>

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk@1539302 13f79535-47bb-0310-9956-ffa450edef68