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.
Make sure the entire process doesn't crash when a message is sent without `type` and/or `data` as such:
```
error: Uncaught Exception TypeError: Cannot read property 'id' of undefined
at Server.gotData (/usr/src/app/node_modules/@trail/pigeoneer/node_modules/node-ipc/dao/socketServer.js:181:24)
at emitOne (events.js:101:20)
at Socket.emit (events.js:188:7)
at Socket.EventEmitter.emit (/usr/src/app/node_modules/@trail/pigeoneer/node_modules/sc-domain/index.js:12:31)
at readableAddChunk (_stream_readable.js:176:18)
at Socket.Readable.push (_stream_readable.js:134:10)
at TCP.onread (net.js:548:20)
```
the function being set to fire after 100ms conflicted with delays in firing the 'disconnect' event on windows, and this resulted in the socket's 'retriesRemianing' being reset after every decrement and thus violatin the 'maxRetries' rule
