I found the tutorial documentation for adding new plugins and buttons, namely
HtmlEditorConfig::get('cms')->enablePlugins('../../tinymce_ssmacron'); // enables plugin
HtmlEditorConfig::get('cms')->insertButtonsAfter('charmap', 'ssmacron'); // positions plugin
I tried that and it works. I put the image manager in the same folder as tinymce_ssmacron (jsparty) and followed the instructions on the moxiecode wiki. However I get no new button for the image manager. The code in the wiki (as far as I understand it) should be
HtmlEditorConfig::get('cms')->enablePlugins('../../imagemanager');
HtmlEditorConfig::get('cms')->insertButtonsAfter('tablecontrols', 'insertimage');
However this has no effect whatsoever. I don't get a new button and thus no image manager.
Does anyone know if Moxiecodes image manager can be used with Silverstripe and if so how? It's a great plugin for uploading images on the fly when editing content.