taken over by the reqeust manager).
Initialise news and addons manager in a separate thread
and not from the network_http thread anymore. Icons are
also downloaded now from the request manager instead
of the network_http.
git-svn-id: svn+ssh://svn.code.sf.net/p/supertuxkart/code/main/trunk@15006 178a84e3-b1eb-0310-8ba1-8eac791a3b58
into three files request, http_request and xml_request.
git-svn-id: svn+ssh://svn.code.sf.net/p/supertuxkart/code/main/trunk@14978 178a84e3-b1eb-0310-8ba1-8eac791a3b58
