Add IPv6 support

bin/nodecoin

@@ -7,12 +7,30 @@ var config      = require('../config'),
 program
   .version('0.0.1')
   .option('-p, --port <port>', 'Port to listen for requests', parseInt)
+  .option('--ipv4 <address>', 'IPV4 interface to listen for requests')
+  .option('--ipv6 <address>', 'IPV6 interface to listen for requests')
   .parse(process.argv);
 
 config.server.port        = program.port || config.server.port;
+config.server.ipv4address = program.ipv4 || config.server.ipv4address;
+config.server.ipv6address = program.ipv6 || config.server.ipv6address;
 
 var app = nodecoin.express.app(config);
 
+if(!config.server.ipv4address){
   http.createServer(app).listen(app.get('port'), function(){
     console.log('NodeCoin server listening on port ' + app.get('port'));
   });
+}
+
+if(config.server.ipv4address){
+  http.createServer(app).listen(app.get('port'), config.server.ipv4address, function(){
+    console.log('NodeCoin server listening on ' + config.server.ipv4address + ' port ' + app.get('port'));
+  });
+}
+
+if(config.server.ipv6address){
+  http.createServer(app).listen(app.get('port'), config.server.ipv6address, function(){
+    console.log('NodeCoin server listening on ' + config.server.ipv6address + ' port ' + app.get('port'));
+  });
+}
\ No newline at end of file

config.js

 exports.server = {
-  port     : 8081
+  port: 8081,
+  ipv4address: '',
+  ipv6address: ''
 };

readme.md

@@ -30,10 +30,30 @@ By default, nodecoin runs on port 8081. You may change it using the --port param
 
     $ nodecoin --port 80
 
-Note that your system may require root access to launch on port 80.
+Note that your system may require root access to launch on port 80. It is also possible to specify the IPv4 interface:
+
+    $ nodecoin -p 8888 --ipv4 127.0.0.1
+
+    NodeCoin server listening on 127.0.0.1 port 8888
+
+Or IPv6 interface:
+
+    $ nodecoin -p 8888 --ipv6 ::1
+
+    NodeCoin server listening on ::1 port 8888
+
+Or both:
+
+    $ nodecoin -p 8888 --ipv4 127.0.0.1 --ipv6 ::1
+
+    NodeCoin server listening on 127.0.0.1 port 8888
+    NodeCoin server listening on ::1 port 8888
+
+Note too that listening to multiple interfaces doesn't imply mutiple program instances: only *one* is running on multiple interfaces.
+
 For more more details on the nodecoin command, run:
 
-    nodecoin -h
+    nodecoin --help
 
 Which displays:
 
@@ -44,6 +64,8 @@ Which displays:
       -h, --help         output usage information
       -V, --version      output the version number
       -p, --port <port>  Port to listen for requests
+      --ipv4 <address>   IPV4 interface to listen for requests
+      --ipv6 <address>   IPV6 interface to listen for requests
 
 ## Disclaimer
 
@@ -54,6 +76,13 @@ Consequently, NodeCoin proposes its own protocol which differs with OpenUDC. How
 
 For the moment NodeCoin is developed only by its author. If you wish to participate/debate on it, you may join OpenUDC XMPP chatroom (open-udc@muc.jappix.com) on [OpenUDC blog](http://www.openudc.org/) (chat is available on the bottom-right corner of the blog) and contact *cgeek*.
 
+# References
+
+* Official OpenUDC project website: <http://www.openudc.org>
+* Official OpenUDC repository: <https://github.com/Open-UDC/open-udc>
+* Other project trying to implement OpenUDC in python: <https://github.com/canercandan/django-openudc>
+* Theoretical reference: [Relativity Theory of Money v2.718, Stephane Laborde - Nov. 2012](http://wiki.creationmonetaire.info/index.php?title=Main_Page)
+
 # License
 
 Copyright (c) 2013 The nodecoin team.