tls: make `tls.connect` accept port and host in `options`

Previous API used form:

    tls.connect(443, "google.com", options, ...)

now it's replaced with:

    tls.connect({port: 443, host: "google.com", ...}, ...)

It simplifies argument parsing in `tls.connect` and makes the API
consistent with other parts.

Fixes #1983.

lib/tls.js

@@ -999,7 +999,7 @@ Server.prototype.SNICallback = function(servername) {
 
 // Target API:
 //
-//  var s = tls.connect(8000, "google.com", options, function() {
+//  var s = tls.connect({port: 8000, host: "google.com"}, function() {
 //    if (!s.authorized) {
 //      s.destroy();
 //      return;
@@ -1011,24 +1011,31 @@ Server.prototype.SNICallback = function(servername) {
 //  });
 //
 //
-// TODO:  make port, host part of options!
-exports.connect = function(port /* host, options, cb */) {
-  // parse args
-  var host, options = {}, cb;
-  for (var i = 1; i < arguments.length; i++) {
-    switch (typeof arguments[i]) {
-      case 'string':
-        host = arguments[i];
-        break;
-
-      case 'object':
-        options = arguments[i];
-        break;
-
-      case 'function':
-        cb = arguments[i];
-        break;
+exports.connect = function(/* [port, host], options, cb */) {
+  var options = {}, cb;
+
+  if (typeof arguments[0] === 'object') {
+    options = arguments[0];
+  } else if (typeof arguments[1] === 'object') {
+    options = arguments[1];
+    options.port = arguments[0];
+  } else if (typeof arguments[2] === 'object') {
+    options = arguments[2];
+    options.port = arguments[0];
+    options.host = arguments[1];
+  } else {
+    // This is what happens when user passes no `options` argument, we can't
+    // throw `TypeError` here because it would be incompatible with old API
+    if (typeof arguments[0] === 'number') {
+      options.port = arguments[0];
     }
+    if (typeof arguments[1] === 'string') {
+      options.host = arguments[1];
+    }
+  }
+
+  if (typeof arguments[arguments.length - 1] === 'function') {
+    cb = arguments[arguments.length - 1];
   }
 
   var socket = new net.Stream();
@@ -1040,7 +1047,7 @@ exports.connect = function(port /* host, options, cb */) {
                             options.rejectUnauthorized === true ? true : false,
                             {
                               NPNProtocols: this.NPNProtocols,
-                              servername: options.servername || host
+                              servername: options.servername || options.host
                             });
 
   if (options.session) {
@@ -1052,7 +1059,7 @@ exports.connect = function(port /* host, options, cb */) {
     cleartext.on('secureConnect', cb);
   }
 
-  socket.connect(port, host);
+  socket.connect(options.port, options.host);
 
   pair.on('secure', function() {
     var verifyError = pair.ssl.verifyError();