(http client + server + ws) Add support for compressing http client requests with gzip. --compress_request argument is used in ws to enable this. The Content-Encoding is set to gzip, and decoded on the server side if present.

ixwebsocket/IXHttp.h

@@ -84,6 +84,7 @@ namespace ix
         int maxRedirects = 5;
         bool verbose = false;
         bool compress = true;
+        bool compressRequest = false;
         Logger logger;
         OnProgressCallback onProgressCallback;
     };