simplified the reload config code a little, moved the tests into their own file, improved coverage

lib/log4js.js

@@ -188,14 +188,7 @@ function getDefaultLogger () {
 var configState = {};
 
 function loadConfigurationFile(filename) {
-  if (filename && 
-      (!configState.lastFilename || 
-       filename !== configState.lastFilename ||
-       !configState.lastMTime || 
-       fs.statSync(filename).mtime !== configState.lastMTime)
-     ) {
-    configState.lastFilename = filename;
-    configState.lastMTime = fs.statSync(filename).mtime;
+  if (filename) {
     return JSON.parse(fs.readFileSync(filename, "utf8"));
   }
   return undefined;
@@ -222,21 +215,23 @@ function configureOnceOff(config, options) {
 }
 
 function reloadConfiguration() {
-  var filename = configState.filename,
-  mtime;
+  var mtime = getMTime(configState.filename);
+  if (!mtime) return;
+
+  if (configState.lastMTime && (mtime.getTime() > configState.lastMTime.getTime())) {
+    configureOnceOff(loadConfigurationFile(configState.filename));
+  }
+  configState.lastMTime = mtime;
+}
+
+function getMTime(filename) {
+  var mtime;
   try {
-    mtime = fs.statSync(filename).mtime;
+    mtime = fs.statSync(configState.filename).mtime;
   } catch (e) {
     getLogger('log4js').warn('Failed to load configuration file ' + filename);
-    return;
-  }
-  if (configState.lastFilename && configState.lastFilename === filename) {
-    if (mtime.getTime() > configState.lastMTime.getTime()) {
-      configureOnceOff(loadConfigurationFile(filename));
-    }
-  } else {
-    configureOnceOff(loadConfigurationFile(filename));
   }
+  return mtime;
 }
 
 function initReloadConfiguration(filename, options) {
@@ -245,6 +240,7 @@ function initReloadConfiguration(filename, options) {
     delete configState.timerId;
   }
   configState.filename = filename;
+  configState.lastMTime = getMTime(filename);
   configState.timerId = setInterval(reloadConfiguration, options.reloadSecs*1000);
 }