Building CKEditor with Custom Plugins

Hi, 

I am looking in to building a production CKEditor 4.3.4 with custom plugins. They are basically, custom "template" plugins. The plugins are all called using buttons. When I just put the plugins in the normal distribution plugin folder they work. But, When I build my custom CKEditor with CKBuilder the plugins work but the icons don't show up in the editor onLoad. Here is what I am doing. 

1. in the source folder, I add the plugins 
   • Plugin.js, dialogs, icons, lang, modules...
   • in the plugin I use the Icons:directive straight out of templates plugin.js. plugin shoud pick up "timstamp.png" in the icons folder of the plugin. see below.
   • CKEDITOR.plugins.add( 'modules',
             {
             //needs to open new dialog
                 requires: 'dialog',
                 lang: 'af,ar,bg,bn,bs,ca,cs,cy,da,de,el,en,en-au,en-ca,en-gb,eo,es,et,eu,fa,fi,fo,fr,fr-ca,gl,gu,he,hi,hr,hu,id,is,it,ja,ka,km,ko,ku,lt,lv,mk,mn,ms,nb,nl,no,pl,pt,pt-br,ro,ru,si,sk,sl,sq,sr,sr-latn,sv,th,tr,ug,uk,vi,zh,zh-cn', 
                 icons: 'timestamp',
                 init : function( editor ) {
                 // Add a new dialog to the plugin
                 CKEDITOR.dialog.add('modules', CKEDITOR.getUrl(this.path + 'dialogs/testdialog.js'));                
                     
                     // create the command for that
                     editor.addCommand( 'modules', new CKEDITOR.dialogCommand( 'modules' ) );
                     // Expose it on the UI with this button that onclick calls the command.
                     editor.ui.addButton && editor.ui.addButton('Modules',
                     {
                         label: 'Textbausteine',
                         command: 'modules'
                         
                     });
2. Build using the ckbuilder.jar 1.72 using the java -jar command in build.sh (not with build.sh) 
3. Load CKEditor (everything works but no icons ) 

Can someone give me a hint what I should do to get it working?