Applied a default to config.socketTimeout, renamed error name to something more specific, added space for style

lib/Connection.js

@@ -56,7 +56,7 @@ function Connection(config) {
 
   this._config = {
     socket: config.socket,
-    socketTimeout: config.socketTimeout,
+    socketTimeout: config.socketTimeout || 0,
     host: config.host || 'localhost',
     port: config.port || 143,
     tls: config.tls,
@@ -158,7 +158,7 @@ Connection.prototype.connect = function() {
     self.debug && self.debug('[connection] Socket timeout');
 
     var err = new Error('Socket timed out while talking to server');
-    err.source = 'timeout';
+    err.source = 'socket-timeout';
     self.emit('error', err);
     socket.destroy();
   };