added the ability to add HTTP headers to the client.

lib/client.js

@@ -43,6 +43,22 @@ Client.prototype.clearSoapHeaders = function() {
   this.soapHeaders = null;
 };
 
+Client.prototype.addHttpHeader = function(name, value) {
+  if (!this.httpHeaders) {
+    this.httpHeaders = {};
+  }
+  this.httpHeaders[name] = value;
+};
+
+Client.prototype.getHttpHeaders = function() {
+  return this.httpHeaders;
+};
+
+Client.prototype.clearHttpHeaders = function() {
+  this.httpHeaders = {};
+};
+
+
 Client.prototype.addBodyAttribute = function(bodyAttribute, name, namespace, xmlns) {
   if (!this.bodyAttributes) {
     this.bodyAttributes = [];
@@ -168,6 +184,7 @@ Client.prototype._invoke = function(method, args, location, callback, options, e
   options = options || {};
 
   //Add extra headers
+  for (var header in this.httpHeaders ) { headers[header] = this.httpHeaders[header];  }
   for (var attr in extraHeaders) { headers[attr] = extraHeaders[attr]; }
 
   // Allow the security object to add headers

test/client-test.js

@@ -267,6 +267,22 @@ describe('SOAP Client', function() {
       done();
     });
   });
+
+  it('should add http headers', function(done) {
+    soap.createClient(__dirname+'/wsdl/default_namespace.wsdl', function(err, client) {
+      assert.ok(client);
+      assert.ok(!client.getHttpHeaders());
+
+      client.addHttpHeader('foo', 'bar');
+
+      assert.ok(client.getHttpHeaders());
+      assert.equal(client.getHttpHeaders().foo, 'bar');
+
+      client.clearHttpHeaders();
+      assert.equal(Object.keys(client.getHttpHeaders()).length, 0);
+      done();
+    });
+  });
 
   describe('Namespace number', function() {
     var server = null;