ENH: added 'headers' to available options, to add or overwrite existing headers

Author: srossross

Diff for: lib/caronte/common.js

@@ -1,6 +1,7 @@
-var common = exports
+var   common = exports
     , http = require('http')
     , https = require('https')
+    , extend = require('util')._extend
     ;
 
 /**
@@ -35,6 +36,10 @@ common.setupOutgoing = function(outgoing, options, req, forward) {
     function(e) { outgoing[e] = req[e]; }
   );
 
+  if (options.headers){
+    extend(outgoing.headers, options.headers);
+  }
+
   if (options.agent){
     outgoing.agent = options.agent;
   }