Fix empty module folder causing errors, fix var naming

Fix a wrongly named class causing ClassNotFound issues,
also added additional checks for empty module folder and
added en moduleFolder directive to configure module location

refs #4092

config/icinga.ini

@@ -3,6 +3,7 @@ environment = development
 timezone    = "Europe/Berlin"
 indexModule = monitoring
 indexController = dashboard
+moduleFolder = "/usr/etc/icinga-modules"
 
 [logging]
 ; General log

library/Icinga/Application/ApplicationBootstrap.php

@@ -100,7 +100,7 @@ abstract class ApplicationBootstrap
     public function moduleManager()
     {
         if ($this->moduleManager === null) {
-            $this->moduleManager = new ModuleManager($this, "/etc/icinga2/modules_enabled");
+            $this->moduleManager = new ModuleManager($this, $this->config->global->moduleFolder);
         }
         return $this->moduleManager;
     }

library/Icinga/Application/Modules/Manager.php

@@ -54,7 +54,7 @@ class Manager
 
     public function select()
     {
-        $source = new \Icinga\Data\ArrayDataSource($this->getModuleInfo());
+        $source = new \Icinga\Data\ArrayDatasource($this->getModuleInfo());
         return $source->select();
     }
 
@@ -238,7 +238,12 @@ class Manager
     public function getModuleInfo()
     {
         $installed = $this->listInstalledModules();
+        
         $info = array();
+        if ($installed === null) {
+            return $info;
+        }
+        
         foreach ($installed as $name) {
             $info[] = (object) array(
                 'name'    => $name,
@@ -265,7 +270,10 @@ class Manager
         if ($this->installedBaseDirs === null) {
             $this->detectInstalledModules();
         }
-        return array_keys($this->installedBaseDirs);
+        
+        if ($this->installedBaseDirs !== null) {
+            return array_keys($this->installedBaseDirs);
+        }
     }
 
     public function detectInstalledModules()

public/js/icinga/container.js

@@ -108,6 +108,5 @@
             containerMgrInstance = new ContainerMgr($,log,widgets,subTable);
         }
         return containerMgrInstance;
-
     });
 })();

public/js/icinga/icinga.js

@@ -80,5 +80,3 @@ define([
     };
     return new Icinga();
 });
-
-

public/js/main.js

@@ -24,4 +24,3 @@ define(['jquery','Holder'], function ($) {
         window.Icinga = Icinga;
     });
 });
-