Cluster module support

Added an option to control whether or not node-ipc unlinks the Unix
socket path when it starts a server which, when set to false, allows the
overall application to handle this and allows node-ipc to work with the
Node.js cluster module.

dao/socketServer.js

@@ -58,10 +58,14 @@ class Server extends Events{
             return;
         }
 
-        fs.unlink(
-            this.path,
-            startServer.bind(this)
-        );
+        if(this.config.unlink){}
+            fs.unlink(
+                this.path,
+                startServer.bind(this)
+            );
+        }else{
+            startServer.bind(this)();
+        }
     }
 }
 

entities/Defaults.js

@@ -28,6 +28,7 @@ class Defaults{
         this.encoding='utf8';
         this.rawBuffer=false;
         this.sync=false;
+        this.unlink=true;
 
         this.delimiter='\f';