YOu either have installed the entire qa1.7.1 ( or have simply replaced your wysiwyg plugin with the one from the dev version as of today Feb 13- 2015)
steps to add new ckEditor plguin:
1- Suppose the plug-in name is "ckEditorPlugin"(so simply place it to ckEditor\plugin\ckEditorPlugin)
2- (pay attention ) most probabely the button name is also ckEditorPlugin(might be different though)
in config.js:
3- // add these two
config.extraAllowedContent= 'img[!src,alt,width,height]';// not always needed
config.extraPlugins= 'ckEditorPlugin';
// and place the button name somethere among other buttons
config.toolbar = [
{ name: 'basic', items: [ 'ckEditorPlugin', 'Italic', 'Underline', 'Strike', 'Subscript', 'Superscript' ] },
{ name: 'color', items: [ 'TextColor', 'BGColor' ] },
{ name: 'align', items: [ 'JustifyLeft', 'JustifyCenter', 'JustifyRight', 'JustifyBlock' ] },
{ name: 'clipboard', items: [ 'Cut', 'Copy', 'Paste', 'PasteFromWord', '-', 'Undo', 'Redo' ] },
'/',
{ name: 'font', items: [ 'Font', 'FontSize', 'Format' ] },
{ name: 'paragraph', items: [ 'NumberedList', 'BulletedList', '-', 'Outdent', 'Indent', 'Blockquote' ] },
{ name: 'links', items: [ 'Link', 'Unlink' ] },
{ name: 'insert', items: [ 'Image', 'Table', 'HorizontalRule', 'SpecialChar', 'Smiley' ] },
{ name: 'last', items: [ 'RemoveFormat', 'Maximize' ] }
];
The onse high lighted in yellow are always needed for new plugins (with button)