Support for disabling log writes on shutdown.

Updated logger.js to support disabling all log writes.
Updated log4js.js shutdown function to disable log writes.
Added tests.
Update gitignore to ignore rolling date stream's test output.

lib/logger.js

@@ -4,6 +4,8 @@ var levels = require('./levels')
 , events = require('events')
 , DEFAULT_CATEGORY = '[default]';
 
+var logWritesEnabled = true;
+
 /**
  * Models a logging event.
  * @constructor
@@ -66,7 +68,7 @@ Logger.prototype.isLevelEnabled = function(otherLevel) {
     };
     
     Logger.prototype[levelString.toLowerCase()] = function () {
-      if (this.isLevelEnabled(level)) {
+      if (logWritesEnabled && this.isLevelEnabled(level)) {
         var args = Array.prototype.slice.call(arguments);
         args.unshift(level);
         Logger.prototype.log.apply(this, args);
@@ -75,6 +77,23 @@ Logger.prototype.isLevelEnabled = function(otherLevel) {
   }
 );
 
+/**
+ * Disable all log writes.
+ * @returns {void}
+ */
+function disableAllLogWrites() {
+  logWritesEnabled = false;
+}
+
+/**
+ * Enable log writes.
+ * @returns {void}
+ */
+function enableAllLogWrites() {
+  logWritesEnabled = true;
+}
 
 exports.LoggingEvent = LoggingEvent;
 exports.Logger = Logger;
+exports.disableAllLogWrites = disableAllLogWrites;
+exports.enableAllLogWrites = enableAllLogWrites;