[sr-dev] New async HTTP module

Hi all, with two colleagues (Camille Oudot and Giacomo Vacca) we have been working to an asynchronous HTTP module. The module uses libevent (http://libevent.org/) and cURL's multi inteface ( http://curl.haxx.se/libcurl/c/libcurl-multi.html). It instantiates N workers at startup, each able to generate multiple requests in parallel and to resume the execution of the routing script upon reception of the HTTP reply (or on error); if the query is executed in a transaction context, the transaction itself will be suspended and resumed before continuing the routing logic execution. The module, apart from implementing non blocking HTTP queries, also provides the ability to specify some HTTPS options per request, to customize HTTP headers and to use several HTTP methods (GET,POST,PUT,DELETE) making it very suitable for interacting with RESTful APIs. We hope that this module can be useful to many. As usual any feedback and improvement proposals are more than welcome! Regards, Federico