Clear all filterpresets when displaying the filter window

 The possiblefilter property in FilterEditor wasn't correctly cleared
 when switching cronks. As the FilterEditor is only constructed once,
 this caused all filters that showed up for different cronks to be summarized. Therefore it was possible to filter for properties that weren't available.

 fixes #3935

app/modules/Cronks/lib/js/Icinga/Cronks/util/FilterEditor.js

@@ -61,26 +61,32 @@ Ext.ns("Icinga.Cronks.util").FilterEditor = Ext.extend(Ext.tree.TreePanel, {
         if(typeof cfg !== "object")
             cfg = {};
         this.filterCfg = cfg.filterCfg;
-        this.grid = cfg.grid,
+        this.grid = cfg.grid;
         this.presets = cfg.presets;
         this.registerFilters();
 
         Ext.tree.TreePanel.prototype.constructor.apply(this,arguments);
         this.addEvents({
             "filterchanged": true
+
         });
     },
 
     registerFilters: function() {
         var known = {};
+        this.possibleFilters = [
+            ['AND','group'],
+            ['OR','group'],
+            ['NOT','group']
+        ];
         for(var i=0;i<this.filterCfg.length;i++) {
             var filter = this.filterCfg[i];
             if (filter.enabled !== true) {
                 continue;
             }
             if(known[filter.label])
                 continue;
-            this.possibleFilters.push([filter.label,'filter',filter])
+            this.possibleFilters.push([filter.label,'filter',filter]);
             this.labelFilterMap[filter.label] = filter;
             known[filter.label] = true;
         }
@@ -277,6 +283,7 @@ Ext.ns("Icinga.Cronks.util").FilterEditor = Ext.extend(Ext.tree.TreePanel, {
         Ext.tree.TreePanel.prototype.initEvents.apply(this,arguments);
         this.on({
             afterlayout: function() {
+                this.registerFilters();
                 if(this.currentState)
                     this.setRootNode(this.nodeFromFilterObject(this.currentState));
 
@@ -391,7 +398,7 @@ Ext.ns("Icinga.Cronks.util").FilterEditor = Ext.extend(Ext.tree.TreePanel, {
             layout:'fit',
             items: this.form
         });
-        this.addctx.setPosition(Ext.EventObject.getXY())
+        this.addctx.setPosition(Ext.EventObject.getXY());
 
         this.addctx.show();