Hopefully managed to put enough hacks in there to make renaming the config file the last step, so if it fails, it can be done manually
tinyMCE.importPluginLanguagePack('visualchars');var TinyMCE_VisualCharsPlugin={getInfo:function(){return{longname:'Visual characters',author:'Moxiecode Systems AB',authorurl:'http://tinymce.moxiecode.com',infourl:'http://wiki.moxiecode.com/index.php/TinyMCE:Plugins/visualchars',version:tinyMCE.majorVersion+"."+tinyMCE.minorVersion}},initInstance:function(inst){inst.visualChars={state:false}},getControlHTML:function(cn){switch(cn){case"visualchars":return tinyMCE.getButtonHTML(cn,'lang_visualchars_desc','{$pluginurl}/images/visualchars.gif','mceVisualChars',false)}return""},execCommand:function(editor_id,element,command,user_interface,value){var inst=tinyMCE.getInstanceById(editor_id);switch(command){case"mceVisualChars":this._toggleVisualChars(editor_id,inst);return true}return false},cleanup:function(type,content,inst){if(type=="insert_to_editor_dom"||type=="get_from_editor_dom"){inst.visualChars.state=true;this._toggleVisualChars(inst.editorId,inst)}return content},_toggleVisualChars:function(editor_id,inst){var nl,i,h,d=inst.getDoc(),b=inst.getBody(),nv,s=inst.selection,bo;inst.visualChars.state=!inst.visualChars.state;bo=s.getBookmark(true);tinyMCE.switchClass(editor_id+'_visualchars',inst.visualChars.state?'mceButtonSelected':'mceButtonNormal');if(inst.visualChars.state){nl=tinyMCE.selectNodes(b,function(n){return n.nodeType==3&&n.nodeValue&&n.nodeValue.indexOf('\u00a0')!=-1});for(i=0;i<nl.length;i++){nv=nl[i].nodeValue;nv=nv.replace(/(\u00a0+)/g,'<span class="mceItemHiddenVisualChar">$1</span>');nv=nv.replace(/\u00a0/g,'\u00b7');tinyMCE.setOuterHTML(nl[i],nv,d)}}else{nl=tinyMCE.selectNodes(b,function(n){return n.nodeType==1&&n.nodeName=='SPAN'&&n.className=='mceItemHiddenVisualChar'});for(i=0;i<nl.length;i++)tinyMCE.setOuterHTML(nl[i],nl[i].innerHTML.replace(/(·|\u00b7)/g,' '),d)}}};tinyMCE.addPlugin("visualchars",TinyMCE_VisualCharsPlugin);