feature: allow passing cwd as an option

lib/log4js.js

@@ -324,14 +324,20 @@ function initReloadConfiguration(filename, options) {
 
 function configure (configurationFileOrObject, options) {
     var config = configurationFileOrObject;
+    options = options || {};
+    if (options.hasOwnProperty('cwd')) {
+        config.appenders.forEach(function(appender) {
+            if (appender.hasOwnProperty('filename')) {
+                 appender.filename = options.cwd + '/' + appender.filename;
+            }
+        });
+    }
     if (config === undefined || config === null || typeof(config) === 'string') {
-        options = options || { };
         if (options.reloadSecs) {
             initReloadConfiguration(config, options);
         }
         configureOnceOff(loadConfigurationFile(config));
     } else {
-        options = options || {};
         if (options.reloadSecs) {
             getLogger('log4js').warn('Ignoring configuration reload parameter for "object" configuration.');
         }